This page contains a collection of quotes on intelligence and understanding, arranged in roughly chronological order. These quotes are all genuine and details about the author, book, chapter number, and translation are included where applicable. Quotes that begin with a section of bold text are my personal favourites. Without further ado, here are sixteen (real) quotes by philosophers on intelligence and understanding:
There are three classes of intellects: one which comprehends by itself; another which appreciates what others comprehended; and a third which neither comprehends by itself nor by the showing of others; the first is the most excellent, the second is good, the third is useless.
– Niccolò Machiavelli, The Prince, XXII, trans. W. K. Marriott
The mind of man is far from the nature of a clear and equal glass, wherein the beams of things should reflect according to their true incidence; nay, it is rather like an enchanted glass, full of superstition and imposture, if it be not delivered and reduced.
– Francis Bacon, The Advancement of Learning, Bk. II, XIV, 9
The human understanding, from its peculiar nature, easily supposes a greater degree of order and equality in things than it really finds.
– Francis Bacon, Novum Organon, I, 45
What of thinking? I find here that thought is an attribute that belongs to me; it alone cannot be separated from me. I am, I exist, that is certain. But how often? Just when I think; for it might possibly be the case if I ceased entirely to think, that I should likewise cease altogether to exist. I do not now admit anything which is not necessarily true: to speak accurately I am not more than a thing which thinks, that is to say a mind or a soul, or an understanding, or a reason, which are terms whose significance was formerly unknown to me. I am, however, a real thing and really exist; but what thing? I have answered: a thing which thinks.
– René Descartes, Meditations on First Philosophy, II, trans. Elizabeth S. Haldane.
There are then two kinds of intellect: the one able to penetrate acutely and deeply into the conclusions of given premises, and this is the precise intellect; the other able to comprehend a great number of premises without confusing them, and this is the mathematical intellect. The one has force and exactness, the other comprehension. Now the one quality can exist without the other; the intellect can be strong and narrow, and can also be comprehensive and weak.
– Blaise Pascal, Pensées, I, 2, trans. W. F. Trotter
I can well conceive a man without hands, feet, head (for it is only experience which teaches us that the head is more necessary than feet). But I cannot conceive man without thought; he would be a stone or a brute.
– Blaise Pascal, Pensées, VI, 339, trans. W. F. Trotter
All our dignity consists . . . in thought. By it we must elevate ourselves, and not by space and time which we cannot fill. Let us endeavour, then, to think well; this is the principle of morality.
– Blaise Pascal, Pensées, VI, 347, trans. W. F. Trotter
It is not from space that I must seek my dignity, but from the government of my thought. I shall have no more if I possess worlds. By space the universe encompasses and swallows me up like an atom; by thought I comprehend the world.
– Blaise Pascal, Pensées, VI, 348, trans. W. F. Trotter
A feeble body makes a feeble mind.
– Jean-Jacques Rousseau, Emile, I, trans. Barbara Foxley
Such is the delight of mental superiority, that none on whom nature or study have conferred it, would purchase the gifts of fortune by its loss.
– Samuel Johnson, The Rambler No. 150
Great intellectual gifts mean an activity pre-eminently nervous in its character, and consequently a very high degree of susceptibility to pain in every form.
– Arthur Schopenhauer, Personality, trans. T. Bailey Saunders
What is the hardest task in the world? To think.
– Ralph Waldo Emerson, Intellect
Consciousness . . . does not appear to itself chopped up in bits. Such words as ‘chain’ or ‘train’ do not describe it fitly as it presents itself in the first instance. It is nothing jointed; it flows. A ‘river’ or a ‘stream’ are the metaphors by which it is most naturally described. In talking of it hereafter, let us call it the stream of thought, of consciousness, or of subjective life.
– William James, Psychology, IX
The man who listens to Reason is lost: Reason enslaves all whose minds are not strong enough to master her.
– George Bernard Shaw, Man and Superman, Maxims for Revolutionists
Real life is, to most men, a long second-best, a perpetual compromise between the ideal and the possible; but the world of pure reason knows no compromise, no practical limitations, no barrier to the creative activity embodying in splendid edifices the passionate aspiration after the perfect from which all great work springs. Remote from human passions, remote even from the pitiful facts of nature, the generations have gradually created an ordered cosmos, where pure thought can dwell as in its natural home, and where one, at least, of our nobler impulses can escape from the dreary exile of the actual world.
– Bertrand Russell, The Study of Mathematics
The power of reason is thought small in these days, but I remain an unrepentant rationalist. Reason may be a small force, but it is constant, and works always in one direction, while the forces of unreason destroy one another in futile strife. Therefore every orgy of unreason in the end strengthens the friends of reason, and shows afresh that they are the only true friends of humanity.
– Bertrand Russell, Sceptical Essays, IX
If you’d like to learn more about philosophy, check out this collection of Resources and Reading Lists.