Reason is the discovery of truth or falsehood. Truth or falsehood consists in an agreement or disagreement either to the real relations of ideas, or to real existence and matter of fact. Whatever, therefore, is not susceptible of this agreement or disagreement, is incapable of being true or false, and can never be an object of our reason. Now ‘tis evident our passions, volitions, and actions, are not susceptible of any such agreement or disagreement; being original facts and realities, complete in themselves, and implying no reference to other passions, volitions, and actions. ‘Tis impossible, therefore, they can be pronounced either true or false, and be either contrary or conformable to reason.

Vice and virtue, therefore, may be compar’d to sounds, colours, heat and cold, which, according to modern philosophy, are not qualities in objects, but perceptions in the mind: and this discovery in morals, like that other in physics, is to be regarded as a considerable advancement of the speculative sciences; tho’, like that too it has little or no influence on practice.

Mortifications have their reward in a state of consciousness that corresponds, on a lower level, to spiritual beatitude. The artist - and the philosopher and the man of science are also artists - knows the bliss of aesthetic contemplation, discovery and non-attached possession. The goods of the intellect, the emotions and the imagination are real goods; but they are not the final good, and when we treat them as ends in themselves, we fall into idolatry. Mortification of will, desire and action is not enough; there must also be mortification in the fields of knowing, thinking feeling and fancying.

The great revolution of our generation is the discovery that human beings, by changing the inner attitudes of their minds, can change the outer aspects of their lives.

The greatest discovery of my generation is that human beings can alter their lives by altering their attitudes.

There is nothing a man can less afford to leave at home than his conscience or his good habits; for it is not to be denied that travel is, in its immediate circumstances, unfavorable to habits of self-discipline, regulation of thought, sobriety of conduct, and dignity of character. Indeed, one of the great lessons of travel is the discovery how much our virtues owe to the support of constant occupation, to the influence of public opinion, and to the force of habit; a discovery very dangerous, if it proceed from an actual yielding to temptations resisted at home, and not from a consciousness of increased power put forth in withstanding them.

Nothing is better than to search for the true God, even if the discovery of Him eludes human capacity, since the very wish to learn, if earnestly entertained, produces untold joys and pleasures.

The rout and destruction of the passions, while a good, is not the ultimate good; the discovery of Wisdom is the surpassing good. When this is found, all the people will sing.

Behold the wretched and dismal slavery of him who is in thrall to pleasures and pains, those utterly capricious and tyrannical master. We, however, must escape to freedom. But this is only possible if we are indifferent to Fortune. Then we shall attain that one overriding blessing - the serenity and exhaltation of a firmly anchored mind. For when error is banished, we shall have the great and satisfying joy that comes from the discovery of truth, plus a kind of disposition and cheerfulness of mind. The source of our pleasure in these things will not derive from their being good, but that they emerge from a good that is one’s own.

To understand anything is to find in it something which is our own, and it is the discovery of ourselves outside us which makes us glad. This relation of understanding is partial, but the relation of love is complete. In love the sense of difference is obliterated and the human soul fulfills its purpose in perfection, transcending the limits of itself and reaching across the threshold of the infinite.

Greater even than the greatest discovery is to keep open the way to future discovery.

Scientific knowledge is constantly changing. A discovery of one year receives confirmation of the next or is thrown aside.

It is the modest, not the presumptuous inquirer, who makes a real and safe progress in the discovery of divine truths.

The basic discovery bout any people is the discovery of the relationship between its men and women.

The discovery of nuclear reactions need not bring about the destruction of mankind any more than the discovery of matches.

The process of scientific discovery is, in effect, a continual flight from wonder.

What is the true end and aim of science but the discovery of the ultimate power - a seeking after God through the study of his ways.

The greatest discovery of my generation is that a human being can alter his life by altering his attitudes of mind.

The outstanding achievement of twentieth-century physics is not the theory of relativity with its welding together of space and time, or the theory of quanta with its present apparent negation of the laws of causation, or the dissection of the atom with the resultant discovery that things are not what they seem; it is the general recognition that we are not yet in contact with the ultimate reality. We are still imprisoned in our cave, with our backs to the light, and can only watch the shadows on the wall.

If scientific discovery has not been an unalloyed blessing, if it has conferred on mankind the power not only to create but also to annihilate, it has at the same time provided humanity with a supreme challenge and a supreme testing.