“My determination is not to remain stubbornly with my ideas, but I’ll leave them and go over to others as soon as I am shown plausible reasons which I can grasp.”

I observed certain animalcules, within whole bodies I saw so quick a motion as to exceed belief; they were about the size of a large grain of sand, and their bodies being transparent, that the internal motion could plainly be seen.

I have divers times endeavoured to see and to know, what parts the Blood consists of; and at length I have observ’d, taking some Blood out of my own hand, that it consists of small round globuls driven through a Crystalline humidity or water.

The whole circumference of each of these streaks was about the thickness of a hair of one’s head. … all consisted of very small green globules joined together: and there were very many small green globules as well. [The earliest recorded observation of the common green alga Spyrogyra.]

I saw this vast number of animalcules not all through the semen, but only in the liquid matter adhering to the thicker part.

Examining this water…I found floating therein divers earthy particles, and some green streaks, spirally wound serpent-wise.

In the year 1657 I discovered very small living creatures in rain water.

I’ve never taught one, because if I taught one, I’d have to teach others. I would give myself over to a slavery, whereas I want to stay a free man.

How inscrutable and incomprehensible are the hidden works of Nature!

Just as the supposed number may differ from the true number by fully 100, 150, or even 200 in a flock of 600 sheep, so may I be even more out of my reckoning in the case of these very little animalcules.

How little do we discover in comparison of those things which now are and forever will be hidden from our sight? The whole of which I am fully persuaded no one will ever be able to dive into, and to explain their causes and effects.

Man comes not from an egg but from an animalcule that is found in male sperm.

Man has always to be busy with his thoughts if anything is to be accomplished.

I’ve spent more time than many will believe [making microscopic observations], but I’ve done them with joy, and I’ve taken no notice those who have said why take so much trouble and what good is it?

I have often endeavoured to view the circulation of the blood in terrestrial animals, but without success, by reason that no parts of their bodies were sufficiently transparent.

For my part, I would say that the male sperm and seeds of plants have been penetrated so far that there is nothing further to discover in this great secret, but I could err in my opinion.

I have divers times endeavoured to see and to know, what parts the Blood consists of; and at length I have observ’d, taking some Blood out of my own hand, that it consists of small round globuls driven through a Crystalline humidity or water.

If you want to get somewhere you have to know where you want to go and how to get there. Then never, never, never give up.

If you want to make a movie, make it. Don’t wait for a grant, don’t wait for the perfect circumstances, just make it.

Trying to determine the structure of a protein by UV spectroscopy was like trying to determine the structure of a piano by listening to the sound it made while being dropped down a flight of stairs.

I don’t give up because I don’t give up. I don’t believe in it.

If your determination is fixed, I do not counsel you to despair. Few things are impossible to diligence and skill. Great works are performed not by strength, but perseverance.

Your actions, and your action alone, determines your worth.

No hours, nor amount of labor, nor amount of money would deter me from giving the best that there was in me.

Characters make their own plot. The dimensions of the characters determine the action of the novel.