“I have oft-times been besought, by divers gentlemen, to set down on paper what I have beheld through my newly invented microscopia, but I have generally declined.”

Among other things, I saw in the body of one of these animalcules a bright and round corpuscle, placed near the head, and in which a very wonderful swift motion was to be seen, consisting of an alternate extension and contraction.

[M]y work, which I’ve done for a long time, was not pursued in order to gain the praise I now enjoy, but chiefly from a craving after knowledge, which I notice resides in me more than in most other men.

In it, that sometimes more than a thousand were moving about in an amount of material the size of a grain of sand…

Whenever I found something remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people be informed thereof.

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

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

And I judge that some of these little creatures were above a thousand times smaller than the smallest ones I have ever yet seen, upon the rind of cheese, in wheaten flour, mould, and the like.

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?

The 31th of May, I perceived in the same water more of those Animals, as also some that were somewhat bigger.

And therewithal, whenever I found out anything remarkable, I have thought it my duty to put down my discovery on paper, so that all ingenious people might be informed thereof.

This particle I concluded to be the heart.

For, the circumference of one of these little Animals in water, is not so big as the thickness of a hair in a Cheese-mite.

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.

What is at a peak is certain to decline. He who shows his hand will surely be defeated. He who can prevail in battle by taking advantage of his enemy’s doubts is invincible.

Our youth and manhood are due to our country, but our declining years are due to ourselves.

Not yet is not no. It is still possible that tomorrow will be more precious than yesterday.

If a nation’s literature declines, the nation atrophies and decays.

I’ve turned down twentysomething million dollars for movies.

We know that if one man’s rights are denied, the rights of all are endangered.

Never do things others can do and will do if there are things others cannot do or will not do.

If inflation-adjusted interest rates decline in a given country, its currency is likely to decline.