Nothing happens by chance.
This is not sentiment, but sober fact: ‘chance’ is not a cause, it is not an active principle which produces an effect. The word ‘chance’ does not refer to any object or force in itself, but rather to our lack of knowledge. The element of chance in any event is the element of the unknown: things that we lack either sufficient knowledge to predict or sufficient power to control.
To take an example: the simplest version of chance is flipping a coin. There is, so to speak, and even chance of its landing heads or tails. However, the outcome a coin toss isn’t random, but is determined but specific laws of motion acting on an object of a specific size and shape. The coin is struck at a particular angle by a particular amount of force, spins a certain number of times and so lands on one of two faces. If a man had sufficient mathematical knowledge coupled with sufficient muscle control, he could predict the outcome of every coin toss with perfect accuracy. It would only be a matter of calculating how many times a coin will turn over when hit with a certain amount of force and allowed to travel a certain distance.
A coin toss is a matter of chance solely because every human being short of an incomparable genius lacks sufficient knowledge or control to predict the outcome.
To take a more specific example, the death of Aeschylus seems like a supreme example of chance happening: an eagle dropped a turtle on his head out of nowhere, mistaking it for a rock. But it’s only chance from the perspective of Aeschylus: it happened for the very clear reason that the bird was hungry, caught a turtle, and, obeying instinct, dropped it on what appeared to be a rock. There was a clear line of events leading up to the fatal turtle drop. It’s only an example of bad fortune because Aeschylus himself had no means of knowing the event was going to happen.
Chance and fortune are simply ways of saying that we are limited creatures who have neither the capacity nor the opportunity to know every relevant factor in any single event.