A Philosophical Essay on Probabilities is the 1814 classic by Pierre-Simon Laplace (1749-1827), the great French mathematician and astronomer, written as an accessible introduction to his monumental work on probability. It is the source of the famous Laplace’s demon, the thought experiment on determinism, and it laid out the principles of probability for the general reader. The essay shaped how science and philosophy alike think about chance and certainty. Free PDF download available on BDeBooks.