Antonie van Leeuwenhoek

I have seen the wonders of the living world, and I have found that life itself is the greatest mystery.

I have often been filled with a sense of purpose, and I have found that my work is a contribution to the understanding of the world.

I have often been told that my observations were impossible, and that I must be mistaken. But I have always found that my observations were correct, and that those who contradicted me were in error.

I have seen, with the greatest astonishment, a prodigious number of living creatures in one drop of water, which were so small that they could not be seen with the naked eye.

I have discovered that the blood is not a homogeneous fluid, but consists of an infinite number of very small globules.

I have seen, with my own eyes, that the semen of a man contains an infinite number of living animalcules, which move about with great agility.

I have often been laughed at for my pains, but I have always found that those who laughed at me were ignorant of what I was doing.

I have made a microscope, which magnifies objects more than a hundred times, and with it I have seen things which no man has ever seen before.

I have observed that the smallest particles of matter are not simple, but are composed of still smaller particles.

I have seen that the muscles are not composed of fibers, but of an infinite number of very small globules.

I have discovered that the brain is not a homogeneous substance, but consists of an infinite number of very small globules.

I have seen that the nerves are not hollow tubes, but are composed of an infinite number of very small fibers.

I have observed that the smallest insects are as perfectly formed as the largest animals.

I have discovered that the flea is not generated from dust, but from an egg, like other insects.

I have seen that the maggots in cheese are not generated from the cheese itself, but from the eggs of flies.

I have observed that the smallest living creatures have organs as perfectly formed as the largest animals.

I have seen that the smallest particles of matter are in perpetual motion.

I have discovered that the blood circulates through the capillaries, which are so small that they cannot be seen with the naked eye.

I have seen that the smallest living creatures are capable of reproduction.

I have observed that the smallest living creatures are capable of sensation and movement.