When all the thoughts are concerning one thing and the person loses interest in other things, the melancholy begins.

The names of the plants ought to be stable [certa], consequently they should be given to stable genera.

A professor can never better distinguish himself in his work than by encouraging a clever pupil, for the true discovers are among them, as comets amongst the stars.

Yet man does recognise himself [as an animal]. But I ask you and the whole world for a generic differentia between man and ape which conforms to the principles of natural history, I certainly know of none... If I were to call man ape or vice versa, I should bring down all the theologians on my head. But perhaps I should still do it according to the rules of science.

I demand of you, and of the whole world, that you show me a generic character... by which to distinguish between Man and Ape. I myself most assuredly know of none.

We admit as many genera as there are different groups of natural species of which the fructification has the same structure.

Stones grow, plants grow, and live, animals grow live and feel.