“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?”

And I imagine, that [ten hundred thousand] of these little Creatures do not equal an ordinary grain of Sand in bigness: And comparing them with a Cheese-mite (which may be seen to move with the naked eye)

Ten hundred thousand of them could not equal the dimensions of a grain of such course Sand.

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.

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.

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 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.

If you want to turn a vision into reality, you have to give 100% and never stop believing in your dream.

The scale of the technology and infrastructure that must be built is unprecedented, and we believe this is the most important problem we can focus on.

I believe we are powerful but we don’t use our minds to full capacity. Your mind is powerful enough to help you attain whatever you want.

I believe in manicures. I believe in overdressing. I believe in primping at leisure and wearing lipsitck.

I’m a workaholic and I don’t believe in ‘no.’ If I’m not sleeping, nobody’s sleeping.

Love and Compassion are the true religions to me. But to develop this, we do not need to believe in any religion.

Believe things will work out.

The key to success is failure.