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

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.

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

For my part, I hold it equally impossible for a small shellfish to be produced without generation as for a whale to have its origin from the mud.

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.

How inscrutable and incomprehensible are the hidden works of Nature!

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.

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.

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.

I must confess... I don't know any tongue but the Nether-Dutch.

I now found that the spider cannot fix its thread to anything without imprinting the hind part of its body on the place, by which pressure it emits an incredible number of excessively small threads diverging in every direction from whence we may conclude that as soon as the threads are exposed to the air, they lose their viscosity or gluey quality.

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.

If any person examines by the microscope that part towards the extremity of the spider's body from whence its thread proceeds, he will observe the spot to be, as it were, surrounded by five several protuberances or risings, each ending in a point and altogether forming a kind of enclosure.

If we now plainly perceive that the passage of the blood from the arteries into the veins of the tadpole is not performed in any other than those vessels, which are so minute as only to admit the passage of a single globule at a time, we may conclude that the same is performed in like manner in our own bodies and in those of other animals.

In treating of the oak, I have considered that the species of it growing in warm climates is superior to that which is produced in cold countries. But we must not imagine this to be the case with all woods; on the contrary, the fir timber grown in cold countries is superior to that produced in warm ones, where its growth is rapid.

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.

Life lives on life - it is cruel, but it is God's will. And it is for our good, of course, because if there weren't little animals to eat up the young mussels, our canals would be choked by those shellfish, for each mother has more than a thousand young ones at a time!

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

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.

No one can pretend to say that a fish is ever killed by heat, for many kinds of fish, in the middle of summer, and in the burning heat of the sun, do either play, as it were, on the surface of the water, or hide themselves under the leaves, weeds, or other substances at the bottom.

People who look for the first time through a microscope say, 'Now I see this, and then I see that,' and even a skilled observer can be fooled. On these observations I have spent more time than many will believe, but I have done them with joy, and I have taken no notice of those who have said, 'Why take so much trouble,' and, 'What good is it?'

We will admit that, out of the mud or sand which is found on the seashore or the beds of our rivers, at low water, shellfish or testaceous animals come forth, but it does not from thence by any means follow that they are produced without any regular course of generation.

When I have supped too heavily of an evening, I drink in the morning a large number of cups of coffee, and that as hot as I can drink it, so that the sweat breaks out on me, and if by so doing I can't restore my body, a whole apothecary's shop couldn't do much, and that is the only thing I have done for years when I have felt a fever.

Roosevelt's magic lay in one facet of his personality: He knew how to take the risk. No other man in public life I knew could so readily take the challenge of the new.

Man was born free, and he is everywhere in chains.

Photography is a major force in explaining man to man.

The world is... the natural setting of, and field for, all my thoughts and all my explicit perceptions. Truth does not inhabit only the inner man, or more accurately, there is no inner man, man is in the world, and only in the world does he know himself.

I am neither a child, a young man, nor an ancient; nor am I of any caste.

I want the municipality to be a helping hand to the man with a desire of sympathy, to help the fallen when it is not in their power to help themselves.

I always looked for a man to rescue me and bring me happiness. I bought into that myth, of course, and looked for my own Prince Charming.

A desire to be observed, considered, esteemed, praised, beloved, and admired by his fellows is one of the earliest as well as the keenest dispositions discovered in the heart of man.

Nonviolence is a powerful and just weapon. which cuts without wounding and ennobles the man who wields it. It is a sword that heals.

Let me first state that I believe that marriage is a sacred union between one man and one woman.

A man must be strong in that profession, he must have vigor of body and mind, yet I am all out of breath if I walk up a hill; I have not the heart to crush even a fly.

An intelligent man is sometimes forced to be drunk to spend time with his fools.

I believe that if a man does a job as well as a woman, he should be paid as much.

For a man to strike any women is most brutal, and I, as well as everyone else, think this far worse than any attempt to shoot, which, wicked as it is, is at least more comprehensible and more courageous.

There is always a type of man who says he loves his fellow men, and expects to make a living at it.

A man may be in as just possession of truth as of a city, and yet be forced to surrender.

The bravest sight in the world is to see a great man struggling against adversity.

If a man is dumb, someone is going to get the best of him, so why not you? If you don't, you're as dumb as he is.

Happy the man who has been able to learn the causes of things.

Work is not man's punishment. It is his reward and his strength and his pleasure.

'Thou shalt not get found out' is not one of God's commandments; and no man can be saved by trying to keep it.

Sex is the most beautiful thing that can take place between a happily married man and his secretary.

Man has done a lot to make himself dangerous and animals get the worst of all of it. But then, man too is an animal.

A writer may tell me that he thinks man will ultimately become an ostrich. I cannot properly contradict him.

I think I had a more European outlook about the body and sex. The body is in no way dirty, and sex is something beautiful to give to and share with a lover. It has nothing to do with promiscuity, because I only believe in being in love with one man at a time.

A woman who thinks she is intelligent demands the same rights as man. An intelligent woman gives up.