By 'God', I understand, a substance which is infinite, independent, supremely intelligent, supremely powerful, and which created both myself and everything else [...] that exists. All these attributes are such that, the more carefully I concentrate on them, the less possible it seems that they could have originated from me alone. So, from what has been said it must be concluded that God necessarily exists.

Travelling is almost like talking with those of other centuries.

Mathematics is a more powerful instrument of knowledge than any other that has been bequeathed to us by human agency.

The mind effortlessly and automatically takes in new ideas, which remain in limbo until verified or rejected by conscious, rational analysis.

Human wisdom remains always one and the same although applied to the most diverse objects and it is no more changed by their diversity than the sunshine is changed by the variety of objects which it illuminates.

The entire method consists in the order and arrangement of the things to which the mind's eye must turn so that we can discover some truth.

The greatest minds are capable of the greatest vices as well as of the greatest virtues.