An Essay on Criticism Part 2

by Alexander Pope

Of all the causes which conspire to blind
Man’s erring judgment, and misguide the mind,
What the weak head with strongest bias rules,
Is pride, the never-failing vice of fools.
Whatever Nature has in worth denied,
She gives in large recruits of needful pride;
For as in bodies, thus in souls, we find
What wants in blood and spirits, swell’d with wind;
Pride, where wit fails, steps in to our defence,
And fills up all the mighty void of sense!
If once right reason drives that cloud away,
Truth breaks upon us with resistless day;
Trust not yourself; but your defects to know,
Make use of ev’ry friend—and ev’ry foe.

A little learning is a dang’rous thing;
Drink deep, or taste not the Pierian spring:

There shallow draughts intoxicate the brain,
And drinking largely sobers us again.
Fir’d at first sight with what the Muse imparts,
In fearless youth we tempt the heights of arts,
While from the bounded level of our mind,
Short views we take, nor see the lengths behind,
But more advanc’d, behold with strange surprise
New, distant scenes of endless science rise!
So pleas’d at first, the tow’ring Alps we try,
Mount o’er the vales, and seem to tread the sky;
Th’ eternal snows appear already past,
And the first clouds and mountains seem the last;
But those attain’d, we tremble to survey
The growing labours of the lengthen’d way,
Th’ increasing prospect tires our wand’ring eyes,
Hills peep o’er hills, and Alps on Alps arise!

A perfect judge will read each work of wit
With the same spirit that its author writ,
Survey the whole, nor seek slight faults to find,
Where nature moves, and rapture warms the mind;
Nor lose, for that malignant dull delight,
The gen’rous pleasure to be charm’d with wit.
But in such lays as neither ebb, nor flow,
Correctly cold, and regularly low,
That shunning faults, one quiet tenour keep;
We cannot blame indeed—but we may sleep.
In wit, as nature, what affects our hearts
Is not th’ exactness of peculiar parts;
‘Tis not a lip, or eye, we beauty call,
But the joint force and full result of all.
Thus when we view some well-proportion’d dome,
(The world’s just wonder, and ev’n thine, O Rome!’
No single parts unequally surprise;
All comes united to th’ admiring eyes;
No monstrous height, or breadth, or length appear;
The whole at once is bold, and regular.

Whoever thinks a faultless piece to see,
Thinks what ne’er was, nor is, nor e’er shall be.
In ev’ry work regard the writer’s end,
Since none can compass more than they intend;
And if the means be just, the conduct true,
Applause, in spite of trivial faults, is due.
As men of breeding, sometimes men of wit,
T’ avoid great errors, must the less commit:
Neglect the rules each verbal critic lays,
For not to know such trifles, is a praise.
Most critics, fond of some subservient art,
Still make the whole depend upon a part:
They talk of principles, but notions prize,
And all to one lov’d folly sacrifice.

Once on a time, La Mancha’s knight, they say,
A certain bard encount’ring on the way,
Discours’d in terms as just, with looks as sage,
As e’er could Dennis of the Grecian stage;
Concluding all were desp’rate sots and fools,
Who durst depart from Aristotle’s rules.
Our author, happy in a judge so nice,
Produc’d his play, and begg’d the knight’s advice,
Made him observe the subject and the plot,
The manners, passions, unities, what not?
All which, exact to rule, were brought about,
Were but a combat in the lists left out.
“What! leave the combat out?” exclaims the knight;
“Yes, or we must renounce the Stagirite.”
“Not so by Heav’n” (he answers in a rage)
“Knights, squires, and steeds, must enter on the stage.”
So vast a throng the stage can ne’er contain.
“Then build a new, or act it in a plain.”

Thus critics, of less judgment than caprice,
Curious not knowing, not exact but nice,
Form short ideas; and offend in arts
(As most in manners) by a love to parts.

Some to conceit alone their taste confine,
And glitt’ring thoughts struck out at ev’ry line;
Pleas’d with a work where nothing’s just or fit;
One glaring chaos and wild heap of wit.
Poets, like painters, thus, unskill’d to trace
The naked nature and the living grace,
With gold and jewels cover ev’ry part,
And hide with ornaments their want of art.
True wit is nature to advantage dress’d,
What oft was thought, but ne’er so well express’d,
Something, whose truth convinc’d at sight we find,
That gives us back the image of our mind.
As shades more sweetly recommend the light,
So modest plainness sets off sprightly wit.
For works may have more wit than does ‘em good,
As bodies perish through excess of blood.

Others for language all their care express,
And value books, as women men, for dress:
Their praise is still—“the style is excellent”:
The sense, they humbly take upon content.
Words are like leaves; and where they most abound,
Much fruit of sense beneath is rarely found.
False eloquence, like the prismatic glass,
Its gaudy colours spreads on ev’ry place;
The face of Nature we no more survey,
All glares alike, without distinction gay:
But true expression, like th’ unchanging sun,
Clears, and improves whate’er it shines upon,
It gilds all objects, but it alters none.
Expression is the dress of thought, and still
Appears more decent, as more suitable;
A vile conceit in pompous words express’d,
Is like a clown in regal purple dress’d:
For diff’rent styles with diff’rent subjects sort,
As several garbs with country, town, and court.
Some by old words to fame have made pretence,
Ancients in phrase, mere moderns in their sense;
Such labour’d nothings, in so strange a style,
Amaze th’ unlearn’d, and make the learned smile.
Unlucky, as Fungoso in the play,
These sparks with awkward vanity display
What the fine gentleman wore yesterday!
And but so mimic ancient wits at best,
As apes our grandsires, in their doublets dress’d.
In words, as fashions, the same rule will hold;
Alike fantastic, if too new, or old;
Be not the first by whom the new are tried,
Not yet the last to lay the old aside.

But most by numbers judge a poet’s song;
And smooth or rough, with them is right or wrong:
In the bright Muse though thousand charms conspire,
Her voice is all these tuneful fools admire,
Who haunt Parnassus but to please their ear,
Not mend their minds; as some to church repair,
Not for the doctrine, but the music there.
These equal syllables alone require,
Tho’ oft the ear the open vowels tire,
While expletives their feeble aid do join,
And ten low words oft creep in one dull line,
While they ring round the same unvaried chimes,
With sure returns of still expected rhymes.
Where’er you find “the cooling western breeze”,
In the next line, it “whispers through the trees”:
If “crystal streams with pleasing murmurs creep”,
The reader’s threaten’d (not in vain) with “sleep”.
Then, at the last and only couplet fraught
With some unmeaning thing they call a thought,
A needless Alexandrine ends the song,
That, like a wounded snake, drags its slow length along.
Leave such to tune their own dull rhymes, and know
What’s roundly smooth, or languishingly slow;
And praise the easy vigour of a line,
Where Denham’s strength, and Waller’s sweetness join.
True ease in writing comes from art, not chance,
As those move easiest who have learn’d to dance.
‘Tis not enough no harshness gives offence,
The sound must seem an echo to the sense.
Soft is the strain when Zephyr gently blows,
And the smooth stream in smoother numbers flows;
But when loud surges lash the sounding shore,
The hoarse, rough verse should like the torrent roar.
When Ajax strives some rock’s vast weight to throw,
The line too labours, and the words move slow;
Not so, when swift Camilla scours the plain,
Flies o’er th’ unbending corn, and skims along the main.
Hear how Timotheus’ varied lays surprise,
And bid alternate passions fall and rise!
While, at each change, the son of Libyan Jove
Now burns with glory, and then melts with love;
Now his fierce eyes with sparkling fury glow,
Now sighs steal out, and tears begin to flow:
Persians and Greeks like turns of nature found,
And the world’s victor stood subdu’d by sound!
The pow’r of music all our hearts allow,
And what Timotheus was, is Dryden now.

Avoid extremes; and shun the fault of such,
Who still are pleas’d too little or too much.
At ev’ry trifle scorn to take offence,
That always shows great pride, or little sense;
Those heads, as stomachs, are not sure the best,
Which nauseate all, and nothing can digest.
Yet let not each gay turn thy rapture move,
For fools admire, but men of sense approve;
As things seem large which we through mists descry,
Dulness is ever apt to magnify.

Some foreign writers, some our own despise;
The ancients only, or the moderns prize.
Thus wit, like faith, by each man is applied
To one small sect, and all are damn’d beside.
Meanly they seek the blessing to confine,
And force that sun but on a part to shine;
Which not alone the southern wit sublimes,
But ripens spirits in cold northern climes;
Which from the first has shone on ages past,
Enlights the present, and shall warm the last;
(Though each may feel increases and decays,
And see now clearer and now darker days.)
Regard not then if wit be old or new,
But blame the false, and value still the true.
Some ne’er advance a judgment of their own,
But catch the spreading notion of the town;
They reason and conclude by precedent,
And own stale nonsense which they ne’er invent.
Some judge of authors’ names, not works, and then
Nor praise nor blame the writings, but the men.
Of all this servile herd, the worst is he
That in proud dulness joins with quality,
A constant critic at the great man’s board,
To fetch and carry nonsense for my Lord.
What woeful stuff this madrigal would be,
In some starv’d hackney sonneteer, or me?
But let a Lord once own the happy lines,
How the wit brightens! how the style refines!
Before his sacred name flies every fault,
And each exalted stanza teems with thought!

The vulgar thus through imitation err;
As oft the learn’d by being singular;
So much they scorn the crowd, that if the throng
By chance go right, they purposely go wrong:
So Schismatics the plain believers quit,
And are but damn’d for having too much wit.

Some praise at morning what they blame at night;
But always think the last opinion right.
A Muse by these is like a mistress us’d,
This hour she’s idoliz’d, the next abus’d;
While their weak heads, like towns unfortified,
Twixt sense and nonsense daily change their side.
Ask them the cause; they’re wiser still, they say;
And still tomorrow’s wiser than today.
We think our fathers fools, so wise we grow;
Our wiser sons, no doubt, will think us so.
Once school divines this zealous isle o’erspread;
Who knew most Sentences, was deepest read;
Faith, Gospel, all, seem’d made to be disputed,
And none had sense enough to be confuted:
Scotists and Thomists, now, in peace remain,
Amidst their kindred cobwebs in Duck Lane.
If Faith itself has different dresses worn,
What wonder modes in wit should take their turn?
Oft, leaving what is natural and fit,
The current folly proves the ready wit;
And authors think their reputation safe
Which lives as long as fools are pleased to laugh.

Some valuing those of their own side or mind,
Still make themselves the measure of mankind;
Fondly we think we honour merit then,
When we but praise ourselves in other men.
Parties in wit attend on those of state,
And public faction doubles private hate.
Pride, Malice, Folly, against Dryden rose,
In various shapes of Parsons, Critics, Beaus;
But sense surviv’d, when merry jests were past;
For rising merit will buoy up at last.
Might he return, and bless once more our eyes,
New Blackmores and new Milbourns must arise;
Nay should great Homer lift his awful head,
Zoilus again would start up from the dead.
Envy will merit, as its shade, pursue,
But like a shadow, proves the substance true;
For envied wit, like Sol eclips’d, makes known
Th’ opposing body’s grossness, not its own.
When first that sun too powerful beams displays,
It draws up vapours which obscure its rays;
But ev’n those clouds at last adorn its way,
Reflect new glories, and augment the day.

Be thou the first true merit to befriend;
His praise is lost, who stays till all commend.
Short is the date, alas, of modern rhymes,
And ‘tis but just to let ‘em live betimes.
No longer now that golden age appears,
When patriarch wits surviv’d a thousand years:
Now length of Fame (our second life) is lost,
And bare threescore is all ev’n that can boast;
Our sons their fathers’ failing language see,
And such as Chaucer is, shall Dryden be.
So when the faithful pencil has design’d
Some bright idea of the master’s mind,
Where a new world leaps out at his command,
And ready Nature waits upon his hand;
When the ripe colours soften and unite,
And sweetly melt into just shade and light;
When mellowing years their full perfection give,
And each bold figure just begins to live,
The treacherous colours the fair art betray,
And all the bright creation fades away!

Unhappy wit, like most mistaken things,
Atones not for that envy which it brings.
In youth alone its empty praise we boast,
But soon the short-liv’d vanity is lost:
Like some fair flow’r the early spring supplies,
That gaily blooms, but ev’n in blooming dies.
What is this wit, which must our cares employ?
The owner’s wife, that other men enjoy;
Then most our trouble still when most admir’d,
And still the more we give, the more requir’d;
Whose fame with pains we guard, but lose with ease,
Sure some to vex, but never all to please;
‘Tis what the vicious fear, the virtuous shun;
By fools ‘tis hated, and by knaves undone!

If wit so much from ign’rance undergo,
Ah let not learning too commence its foe!
Of old, those met rewards who could excel,
And such were prais’d who but endeavour’d well:
Though triumphs were to gen’rals only due,
Crowns were reserv’d to grace the soldiers too.
Now, they who reach Parnassus’ lofty crown,
Employ their pains to spurn some others down;

And while self-love each jealous writer rules,
Contending wits become the sport of fools:
But still the worst with most regret commend,
For each ill author is as bad a friend.
To what base ends, and by what abject ways,
Are mortals urg’d through sacred lust of praise!
Ah ne’er so dire a thirst of glory boast,
Nor in the critic let the man be lost!
Good nature and good sense must ever join;

To err is human; to forgive, divine.

But if in noble minds some dregs remain,
Not yet purg’d off, of spleen and sour disdain,
Discharge that rage on more provoking crimes,
Nor fear a dearth in these flagitious times.
No pardon vile obscenity should find,
Though wit and art conspire to move your mind;
But dulness with obscenity must prove
As shameful sure as impotence in love.
In the fat age of pleasure, wealth, and ease,
Sprung the rank weed, and thriv’d with large increase:
When love was all an easy monarch’s care;
Seldom at council, never in a war:
Jilts ruled the state, and statesmen farces writ;
Nay wits had pensions, and young Lords had wit:
The fair sat panting at a courtier’s play,
And not a mask went unimprov’d away:
The modest fan was lifted up no more,
And virgins smil’d at what they blush’d before.
The following licence of a foreign reign
Did all the dregs of bold Socinus drain;
Then unbelieving priests reform’d the nation,
And taught more pleasant methods of salvation;
Where Heav’n’s free subjects might their rights dispute,
Lest God himself should seem too absolute:
Pulpits their sacred satire learned to spare,
And Vice admired to find a flatt’rer there!
Encourag’d thus, wit’s Titans brav’d the skies,
And the press groan’d with licenc’d blasphemies.
These monsters, critics! with your darts engage,
Here point your thunder, and exhaust your rage!
Yet shun their fault, who, scandalously nice,
Will needs mistake an author into vice;
All seems infected that th’ infected spy,
As all looks yellow to the jaundic’d eye.


  • An Essay on Criticism: Part 2
  • A little Learning is a dangerous thing 一知半解危害大,知之为知之,不知为不知
  • To err is human; to forgive, divine. 犯错是人,宽恕是神。

An Essay on Criticism Part 1

by Alexander Pope

Si quid novisti rectius istis,
Candidus imperti; si non, his utere mecum
[If you have come to know any precept more correct than these, share it with me, brilliant one; if not, use these with me] (Horace, Epistle I.6.67)

PART 1
‘Tis hard to say, if greater want of skill
Appear in writing or in judging ill;
But, of the two, less dang’rous is th’ offence
To tire our patience, than mislead our sense.
Some few in that, but numbers err in this,
Ten censure wrong for one who writes amiss;
A fool might once himself alone expose,
Now one in verse makes many more in prose.

‘Tis with our judgments as our watches, none
Go just alike, yet each believes his own.
In poets as true genius is but rare,
True taste as seldom is the critic’s share;
Both must alike from Heav’n derive their light,
These born to judge, as well as those to write.
Let such teach others who themselves excel,
And censure freely who have written well.
Authors are partial to their wit, ‘tis true,
But are not critics to their judgment too?

Yet if we look more closely we shall find
Most have the seeds of judgment in their mind;
Nature affords at least a glimm’ring light;
The lines, tho’ touch’d but faintly, are drawn right.
But as the slightest sketch, if justly trac’d,
Is by ill colouring but the more disgrac’d,
So by false learning is good sense defac’d;
Some are bewilder’d in the maze of schools,
And some made coxcombs Nature meant but fools.
In search of wit these lose their common sense,
And then turn critics in their own defence:
Each burns alike, who can, or cannot write,
Or with a rival’s, or an eunuch’s spite.
All fools have still an itching to deride,
And fain would be upon the laughing side.
If Mævius scribble in Apollo’s spite,
There are, who judge still worse than he can write.

Some have at first for wits, then poets pass’d,
Turn’d critics next, and prov’d plain fools at last;
Some neither can for wits nor critics pass,
As heavy mules are neither horse nor ass.
Those half-learn’d witlings, num’rous in our isle
As half-form’d insects on the banks of Nile;
Unfinish’d things, one knows not what to call,
Their generation’s so equivocal:
To tell ‘em, would a hundred tongues require,
Or one vain wit’s, that might a hundred tire.

But you who seek to give and merit fame,
And justly bear a critic’s noble name,
Be sure your self and your own reach to know,
How far your genius, taste, and learning go;
Launch not beyond your depth, but be discreet,
And mark that point where sense and dulness meet.

Nature to all things fix’d the limits fit,
And wisely curb’d proud man’s pretending wit:
As on the land while here the ocean gains,
In other parts it leaves wide sandy plains;
Thus in the soul while memory prevails,
The solid pow’r of understanding fails;
Where beams of warm imagination play,
The memory’s soft figures melt away.
One science only will one genius fit;
So vast is art, so narrow human wit:
Not only bounded to peculiar arts,
But oft in those, confin’d to single parts.
Like kings we lose the conquests gain’d before,
By vain ambition still to make them more;
Each might his sev’ral province well command,
Would all but stoop to what they understand.

First follow NATURE, and your judgment frame
By her just standard, which is still the same:
Unerring Nature, still divinely bright,
One clear, unchang’d, and universal light,
Life, force, and beauty, must to all impart,
At once the source, and end, and test of art.
Art from that fund each just supply provides,
Works without show, and without pomp presides:
In some fair body thus th’ informing soul
With spirits feeds, with vigour fills the whole,
Each motion guides, and ev’ry nerve sustains;
Itself unseen, but in th’ effects, remains.
Some, to whom Heav’n in wit has been profuse,
Want as much more, to turn it to its use;
For wit and judgment often are at strife,
Though meant each other’s aid, like man and wife.
‘Tis more to guide, than spur the Muse’s steed;
Restrain his fury, than provoke his speed;
The winged courser, like a gen’rous horse,
Shows most true mettle when you check his course.

Those RULES of old discover’d, not devis’d,
Are Nature still, but Nature methodis’d;
Nature, like liberty, is but restrain’d
By the same laws which first herself ordain’d.

Hear how learn’d Greece her useful rules indites,
When to repress, and when indulge our flights:
High on Parnassus’ top her sons she show’d,
And pointed out those arduous paths they trod;
Held from afar, aloft, th’ immortal prize,
And urg’d the rest by equal steps to rise.
Just precepts thus from great examples giv’n,
She drew from them what they deriv’d from Heav’n.
The gen’rous critic fann’d the poet’s fire,
And taught the world with reason to admire.
Then criticism the Muse’s handmaid prov’d,
To dress her charms, and make her more belov’d;
But following wits from that intention stray’d;
Who could not win the mistress, woo’d the maid;
Against the poets their own arms they turn’d,
Sure to hate most the men from whom they learn’d.
So modern ‘pothecaries, taught the art
By doctor’s bills to play the doctor’s part,
Bold in the practice of mistaken rules,
Prescribe, apply, and call their masters fools.
Some on the leaves of ancient authors prey,
Nor time nor moths e’er spoil’d so much as they:
Some drily plain, without invention’s aid,
Write dull receipts how poems may be made:
These leave the sense, their learning to display,
And those explain the meaning quite away.

You then whose judgment the right course would steer,
Know well each ANCIENT’S proper character;
His fable, subject, scope in ev’ry page;
Religion, country, genius of his age:
Without all these at once before your eyes,
Cavil you may, but never criticise.
Be Homer’s works your study and delight,
Read them by day, and meditate by night;
Thence form your judgment, thence your maxims bring,
And trace the Muses upward to their spring;
Still with itself compar’d, his text peruse;
And let your comment be the Mantuan Muse.

When first young Maro in his boundless mind
A work t’ outlast immortal Rome design’d,
Perhaps he seem’d above the critic’s law,
And but from Nature’s fountains scorn’d to draw:
But when t’ examine ev’ry part he came,
Nature and Homer were, he found, the same.
Convinc’d, amaz’d, he checks the bold design,
And rules as strict his labour’d work confine,
As if the Stagirite o’erlook’d each line.
Learn hence for ancient rules a just esteem;
To copy nature is to copy them.

Some beauties yet, no precepts can declare,
For there’s a happiness as well as care.
Music resembles poetry, in each
Are nameless graces which no methods teach,
And which a master-hand alone can reach.
If, where the rules not far enough extend,
(Since rules were made but to promote their end)
Some lucky LICENCE answers to the full
Th’ intent propos’d, that licence is a rule.
Thus Pegasus, a nearer way to take,
May boldly deviate from the common track.
Great wits sometimes may gloriously offend,
And rise to faults true critics dare not mend;
From vulgar bounds with brave disorder part,
And snatch a grace beyond the reach of art,
Which, without passing through the judgment, gains
The heart, and all its end at once attains.
In prospects, thus, some objects please our eyes,
Which out of nature’s common order rise,
The shapeless rock, or hanging precipice.
But tho’ the ancients thus their rules invade,
(As kings dispense with laws themselves have made)
Moderns, beware! or if you must offend
Against the precept, ne’er transgress its end;
Let it be seldom, and compell’d by need,
And have, at least, their precedent to plead.
The critic else proceeds without remorse,
Seizes your fame, and puts his laws in force.

I know there are, to whose presumptuous thoughts
Those freer beauties, ev’n in them, seem faults.
Some figures monstrous and misshap’d appear,
Consider’d singly, or beheld too near,
Which, but proportion’d to their light, or place,
Due distance reconciles to form and grace.
A prudent chief not always must display
His pow’rs in equal ranks, and fair array,
But with th’ occasion and the place comply,
Conceal his force, nay seem sometimes to fly.
Those oft are stratagems which errors seem,
Nor is it Homer nods, but we that dream.

Still green with bays each ancient altar stands,
Above the reach of sacrilegious hands,
Secure from flames, from envy’s fiercer rage,
Destructive war, and all-involving age.
See, from each clime the learn’d their incense bring!
Hear, in all tongues consenting pæans ring!
In praise so just let ev’ry voice be join’d,
And fill the gen’ral chorus of mankind!
Hail, bards triumphant! born in happier days;
Immortal heirs of universal praise!
Whose honours with increase of ages grow,
As streams roll down, enlarging as they flow!
Nations unborn your mighty names shall sound,
And worlds applaud that must not yet be found!
Oh may some spark of your celestial fire
The last, the meanest of your sons inspire,
(That on weak wings, from far, pursues your flights;
Glows while he reads, but trembles as he writes)
To teach vain wits a science little known,
T’ admire superior sense, and doubt their own!


Computational Thinking

by Jeannette Wing

It represents a universally applicable attitude and skill set everyone, not just computer scientists, would be eager to learn and use.

Computational thinking builds on the power and limits of computing processes, whether they are executed by a human or by a machine. Computational methods and models give us the courage to solve problems and design systems that no one of us would be capable of tackling alone. Computational thinking confronts the riddle of machine intelligence: What can humans do better than computers? and
What can computers do better than humans? Most fundamentally it addresses the question: What is computable? Today, we know only parts of the answers to such questions.

Computational thinking is a fundamental skill for everyone, not just for computer scientists. To reading, writing, and arithmetic, we should add computational thinking to every child’s analytical ability. Just as the printing press facilitated the spread of the three Rs, what is appropriately incestuous about this vision is that computing and computers facilitate the spread of computational thinking.

Computational thinking involves solving problems, designing systems, and understanding human behavior, by drawing on the concepts fundamental to computer science. Computational thinking includes a range of mental tools that reflect the breadth of the field of computer science.

Having to solve a particular problem, we might ask: How difficult is it to solve? and What’s the best way to solve it? Computer science rests on solid theoretical underpinnings to answer such questions precisely. Stating the difficulty of a problem accounts for the underlying power of the machine—the computing device that will run the solution. We must consider the machine’s instruction set, its resource constraints, and its operating environment.

In solving a problem efficiently, we might further ask whether an approximate solution is good
enough, whether we can use randomization to our advantage, and whether false positives or false negatives are allowed. Computational thinking is reformulating a seemingly difficult problem into one we know how to solve, perhaps by reduction, embedding, transformation, or simulation.

Computational thinking is thinking recursively. It is parallel processing. It is interpreting code as data and data as code. It is type checking as the generalization of dimensional analysis. It is recognizing both the virtues and the dangers of aliasing, or giving someone or something more than one name. It is recognizing both the cost and power of indirect addressing and procedure call. It is judging a program not just for correctness and efficiency but for aesthetics, and a system’s design for simplicity and elegance.

Computational thinking is using abstraction and decomposition when attacking a large complex task
or designing a large complex system. It is separation of concerns. It is choosing an appropriate representation for a problem or modeling the relevant aspects of a problem to make it tractable. It is using invariants to describe a system’s behavior succinctly and declaratively. It is having the confidence we can safely use, modify, and influence a large complex system without understanding its every detail. It is modularizing something in anticipation of multiple users or prefetching and caching in anticipation of future use.

Thinking like a computer scientist means more than being able to program a computer. It requires thinking at multiple levels of abstraction.

Computational thinking is thinking in terms of prevention, protection, and recovery from worst-case
scenarios through redundancy, damage containment, and error correction. It is calling gridlock deadlock and contracts interfaces. It is learning to avoid race conditions when synchronizing meetings with one another.

Computational thinking is using heuristic reasoning to discover a solution. It is planning, learning, and scheduling in the presence of uncertainty. It is search, search, and more search, resulting in a list of Web pages, a strategy for winning a game, or a counterexample. Computational thinking is using massive amounts of data to speed up computation. It is making trade-offs between time and space and between processing power and storage capacity.

Consider these everyday examples: When your daughter goes to school in the morning, she puts in her backpack the things she needs for the day; that’s prefetching and caching. When your son loses his
mittens, you suggest he retrace his steps; that’s backtracking. At what point do you stop renting skis and buy yourself a pair?; that’s online algorithms. Which line do you stand in at the supermarket?; that’s performance modeling for multi-server systems. Why does your telephone still work during a power outage?; that’s independence of failure and redundancy in design. How do Completely Automated Public Turing Test(s) to Tell Computers and Humans Apart, or CAPTCHAs, authenticate humans?; that’s exploiting the difficulty of solving hard AI problems to foil computing agents.

Computational thinking will have become ingrained in everyone’s lives when words like algorithm and precondition are part of everyone’s vocabulary; when nondeterminism and garbage collection take on the meanings used by computer scientists; and when trees are drawn upside down.

We have witnessed the influence of computational thinking on other disciplines. For example, machine learning has transformed statistics. Statistical learning is being used for problems on a scale, in terms of both data size and dimension, unimaginable only a few years ago. Statistics departments in all kinds of organizations are hiring computer scientists. Schools of computer science are embracing existing or starting up new statistics departments.

Computer scientists’recent interest in biology is driven by their belief that biologists can benefit from computational thinking. Computer science’s contribution to biology goes beyond the ability to search through vast amounts of sequence data looking for patterns. The hope is that data structures and algorithms—our computational abstractions and methods—can represent the structure of proteins in ways that elucidate their function. Computational biology is changing the way biologists
think. Similarly, computational game theory is changing the way economists think; nanocomputing, the way chemists think; and quantum computing, the way physicists think.

This kind of thinking will be part of the skill set of not only other scientists but of everyone else. Ubiquitous computing is to today as computational thinking is to tomorrow. Ubiquitous computing was yesterday’s dream that became today’s reality; computational thinking is tomorrow’s reality.

WHAT IT IS, AND ISN’T

Computer science is the study of computation — what can be computed and how to compute it. Computational thinking thus has the following characteristics:

Conceptualizing, not programming. Computer science is not computer programming. Thinking like a computer scientist means more than being able to program a computer. It requires thinking at multiple levels of abstraction;

Fundamental, not rote skill. A fundamental skill is something every human being must know to function in modern society. Rote means a mechanical routine. Ironically, not until computer science solves the AI Grand Challenge of making computers think like humans will thinking be rote;

A way that humans, not computers, think. Computational thinking is a way humans solve problems; it is not trying to get humans to think like computers. Computers are dull and boring; humans are clever and imaginative. We humans make computers exciting. Equipped with computing devices, we use our cleverness to tackle problems we would not dare take on before the age of computing and build systems with functionality limited only by our imaginations;

Complements and combines mathematical and engineering thinking. Computer science inherently draws on mathematical thinking, given that, like all sciences, its formal foundations rest on mathematics.
Computer science inherently draws on engineering thinking, given that we build systems that interact with the real world. The constraints of the underlying computing device force computer scientists to think computationally, not just mathematically. Being free to build virtual worlds
enables us to engineer systems beyond the physical world;

Ideas, not artifacts. It’s not just the software and hardware artifacts we produce that will be physically present everywhere and touch our lives all the time, it will be the computational concepts we use to approach and solve problems, manage our daily lives, and communicate and interact
with other people; and

For everyone, everywhere. Computational thinking will be a reality when it is so integral to human
endeavors it disappears as an explicit philosophy.

Many people equate computer science with computer programming. Some parents see only a narrow range of job opportunities for their children who major in computer science. Many people think the fundamental research in computer science is done and that only the engineering remains. Computational thinking is a grand vision to guide computer science educators, researchers, and practitioners as we act to change society’s image of the field. We especially need to reach the pre-college audience, including teachers, parents, and students, sending them two main messages:

Intellectually challenging and engaging scientific problems remain to be understood and solved. The problem domain and solution domain are limited only by our own curiosity and creativity; and One can major in computer science and do anything. One can major in English or mathematics and go on to a multitude of different careers. Ditto computer science. One can major in computer science and go on to a career in medicine, law, business, politics, any type of science or engineering, and even the arts.

Professors of computer science should teach a course called “Ways to Think Like a Computer Scientist” to college freshmen, making it available to non-majors, not just to computer science majors. We should expose pre-college students to computational methods and models. Rather than bemoan the decline of interest in computer science or the decline in funding for research in computer science, we should look to inspire the public’s interest in the intellectual adventure of the field. We’ll thus spread the joy, awe, and power of computer science, aiming to make computational thinking commonplace.

The Star

by Jane Taylor

Twinkle, twinkle, little star,
How I wonder what you are!
Up above the world so high,
Like a diamond in the sky.

When the blazing sun is gone,
When he nothing shines upon,
Then you show your little light,
Twinkle, twinkle, all the night.

Then the trav’ller in the dark,
Thanks you for your tiny spark,
He could not see which way to go,
If you did not twinkle so.

In the dark blue sky you keep,
And often thro’ my curtains peep,
For you never shut your eye,
Till the sun is in the sky.

‘Tis your bright and tiny spark,
Lights the trav’ller in the dark,
Tho’ I know not what you are,
Twinkle, twinkle, little star.


My English Words List - June - 2022

walkathon

walkathon

noun

  • a walk covering a considerable distance organized especially to raise money for a cause

The children playing the Band on the occasion of International Day of Older Persons at a Intergenerational Walkathon of the Senior Citizens in New Delhi on October 01, 2006

Walkathon

pledge

pledge

noun

To make a pledge or donation, please call the charity’s office.

breakdown

breakdown

noun

the breakdown of water into hydrogen and oxygen

a budget breakdown

ellipse

ellipse

noun

An ellipse (red) obtained as the intersection of a cone with an inclined plane.

  • oval
  • a shape that looks like a flattened circle

Ellipse

genre

genre

noun

This book is a classic of the mystery genre.

mend

mend

verb

The town needs to mend these roads.

It’s never too late to mend.

criterion

criterion

noun

the university’s criteria for admission

moderator

moderator

noun

The moderator allowed audience members to ask the governor questions.

She acts as the moderator in our office meetings.

vend

vend

verb

vends snack foods and novelties at fairs

A snack food vending machine in Hong Kong

Vending machine

vendor

vendor

noun

we’re thinking of making a deal with that other software vendor

Vendor

dispense

dispense

verb

dispense food among the needy

The ATM only dispenses $20 bills.

dispensing pills to their patients

Pharmacists are certified to dispense medication.

rim

rim

noun

He bought stainless steel rims for his new car.

Scratched rim on a one-piece alloy wheel. The black residue remains from where the tire was seated on the "safety profile" rim.

Rim (wheel)

precaution

precaution

noun

When driving, she always wears her seatbelt as a precaution.

Every home owner should take precautions against fire.

wrestling

wrestling

noun

My favorite sport is wrestling.

Arm Wrestling

Arm wrestling

juggle

juggle

verb

He juggled four balls at once.

Children performing juggling as part of the International Jugglers' Association supported Mobile Mini Circus for Children

Juggling a soccer ball

Juggling

alias

alias

noun

He checked into the hotel using an alias.

breach

breach

noun

Many people consider her decision to be a breach of trust.

escort

escort

noun

Everyone was surprised when she arrived at the party without an escort.

linen

linen

noun

A linen handkerchief with drawn thread work around the edges

  • clothing or household articles made of linen cloth or similar fabric
  • household articles (as tablecloths or sheets) or clothing that were once often made of linen

She washes the linen every week.

Linen

orangutan

orangutan

noun

Bornean orangutan

Orangutan

desperate

desperate

adjective

The collapse of her business had made her desperate.

As the supply of food ran out, people became desperate.

We could hear their desperate cries for help.

a desperate struggle to defeat the enemy

aggregate

aggregate

adjective

aggregate sales

An aggregate function performs a calculation on a set of values, and returns a single value.

Aggregate functions are often used with the GROUP BY clause of the SELECT statement.

novice

novice

noun

a novice at skiing

jersey

jersey

noun

  • a shirt made of knitted fabric and especially one worn by a sports team

A modern cycling jersey

a football jersey

Jersey (clothing)

castanet

castanet

noun

Castanets

Castanets

Thanatopsis

by William Cullen Bryant

To him who in the love of Nature holds
Communion with her visible forms, she speaks
A various language; for his gayer hours
She has a voice of gladness, and a smile
And eloquence of beauty, and she glides
Into his darker musings, with a mild
And healing sympathy, that steals away
Their sharpness, ere he is aware. When thoughts
Of the last bitter hour come like a blight
Over thy spirit, and sad images
Of the stern agony, and shroud, and pall,
And breathless darkness, and the narrow house,
Make thee to shudder, and grow sick at heart;—
Go forth, under the open sky, and list
To Nature’s teachings, while from all around—
Earth and her waters, and the depths of air—
Comes a still voice—
Yet a few days, and thee
The all-beholding sun shall see no more
In all his course; nor yet in the cold ground,
Where thy pale form was laid, with many tears,
Nor in the embrace of ocean, shall exist
Thy image. Earth, that nourished thee, shall claim
Thy growth, to be resolved to earth again,
And, lost each human trace, surrendering up
Thine individual being, shalt thou go
To mix for ever with the elements,
To be a brother to the insensible rock
And to the sluggish clod, which the rude swain
Turns with his share, and treads upon. The oak
Shall send his roots abroad, and pierce thy mould.

Yet not to thine eternal resting-place
Shalt thou retire alone, nor couldst thou wish
Couch more magnificent. Thou shalt lie down
With patriarchs of the infant world—with kings,
The powerful of the earth—the wise, the good,
Fair forms, and hoary seers of ages past,
All in one mighty sepulchre. The hills
Rock-ribbed and ancient as the sun,—the vales
Stretching in pensive quietness between;
The venerable woods—rivers that move
In majesty, and the complaining brooks
That make the meadows green; and, poured round all,
Old Ocean’s gray and melancholy waste,—
Are but the solemn decorations all
Of the great tomb of man. The golden sun,
The planets, all the infinite host of heaven,
Are shining on the sad abodes of death,
Through the still lapse of ages. All that tread
The globe are but a handful to the tribes
That slumber in its bosom.—Take the wings
Of morning, pierce the Barcan wilderness,
Or lose thyself in the continuous woods
Where rolls the Oregon, and hears no sound,
Save his own dashings—yet the dead are there:
And millions in those solitudes, since first
The flight of years began, have laid them down
In their last sleep—the dead reign there alone.

So shalt thou rest, and what if thou withdraw
In silence from the living, and no friend
Take note of thy departure? All that breathe
Will share thy destiny. The gay will laugh
When thou art gone, the solemn brood of care
Plod on, and each one as before will chase
His favorite phantom; yet all these shall leave
Their mirth and their employments, and shall come
And make their bed with thee. As the long train
Of ages glide away, the sons of men,
The youth in life’s green spring, and he who goes
In the full strength of years, matron and maid,
The speechless babe, and the gray-headed man—
Shall one by one be gathered to thy side,
By those, who in their turn shall follow them.
So live, that when thy summons comes to join
The innumerable caravan, which moves
To that mysterious realm, where each shall take
His chamber in the silent halls of death,
Thou go not, like the quarry-slave at night,
Scourged to his dungeon, but, sustained and soothed
By an unfaltering trust, approach thy grave,
Like one who wraps the drapery of his couch
About him, and lies down to pleasant dreams.


Work

by Eliza Cook

Work, work, my boy, be not afraid;
Look labor boldly in the face;
Take up the hammer or the spade,
And blush not for your humble place.

There’s glory in the shuttle’s song;
There’s triumph in the anvil’s stroke;
There’s merit in the brave and strong
Who dig the mine or fell the oak.

The wind disturbs the sleeping lake,
And bids it ripple pure and fresh;
It moves the green boughs till they make
Grand music in their leafy mesh.

And so the active breath of life
Should stir our dull and sluggard wills;
For are we not created rife
With health, that stagnant torpor kills?

I doubt if he who lolls his head
Where idleness and plenty meet,
Enjoys his pillow or his bread
As those who earn the meals they eat.

And man is never half so blest
As when the busy day is spent
So as to make his evening rest
A holiday of glad content.