The laws of nature are the rules according to which the effects are produced; but there must be a cause which operates according to these rules. The laws of navigation never navigated a ship. The rules of architecture never built a house.

I sit in my loft with the haves and look out at the have-nots - the bottom of the bottom - and I have to rationalize it, ... Am I pushing out the homeless?

Every conjecture we can form with regard to the works of God has as little probability as the conjectures of a child with regard to the works of an adult.

It appears evident, therefore, that those actions only can truly be called virtuous, and deserving of moral approbation, which the agent believed to be right, and to which he was influenced, more or less, by that belief.

The rules of navigation never navigated a ship. The rules of architecture never built a house.

A philosopher is, no doubt, entitled to examine even those distinctions that are to be found in the structure of all languages... in that case, such a distinction may be imputed to a vulgar error, which ought to be corrected in philosophy.

It is the invaluable merit of the great Basle mathematician Leonard Euler, to have freed the analytical calculus from all geometric bounds, and thus to have established analysis as an independent science, which from his time on has maintained an unchallenged leadership in the field of mathematics.