Leonardo da Vinci on Truth

"Man has much power of discourse which for the most part is vain and false; animals have but little, but it is useful and true, and a small truth is better than a great lie."

"Fire destroys falsehood, that is sophistry, and restores truth, driving out darkness."

"Many have made a trade of delusions and false miracles, deceiving the stupid multitude. Pharisees — that is to say, friars."

"No small hole can so modify the convergence of rays of light as to prevent, at a long distance, the transmission of the true form of the luminous body causing them."

"To lie is so vile, that even if it were in speaking well of godly things it would take off something from God's grace; and Truth is so excellent, that if it praises but small things they become noble."

"Truth at last cannot be hidden. Dissimulation is of no avail. Dissimulation is to no purpose before so great a judge. Falsehood puts on a mask. Nothing is hidden under the sun."

"Fire may be represented as the destroyer of all sophistry, and as the image and demonstration of truth; because it is light and drives out darkness which conceals all essences ."

"Truth here makes Falsehood torment lying tongues."

"Truth was the only daughter of Time."

"Surely when a man is painting a picture he ought not refuse to hear any man's opinion... Since men are able to form a true judgement as to the works of nature, how much more does it behoove us to admit that they are able to judge our faults. Therefore you should be desirous of hearing patiently the opinions of others, and consider and reflect carefully whether or no he who censures you has reason for his censure; and correct your work if you find that he is right, but if not, then let it seem that you have not understood him, or, in case he is a man whom you esteem, show him by argument why it is that he is mistaken."

"Many will think they may reasonably blame me by alleging that my proofs are opposed to the authority of certain men held in the highest reverence by their inexperienced judgments; not considering that my works are the issue of pure and simple experience, who is the one true mistress. These rules are sufficient to enable you to know the true from the false — and this aids men to look only for things that are possible and with due moderation — and not to wrap yourself in ignorance, a thing which can have no good result, so that in despair you would give yourself up to melancholy."