The first widely accepted system of biological classification was developed by Aristotle, a Greek philosopher and scientist.

Aristotle classified organisms into two groups:

* Plants: These were characterized by their lack of movement and their ability to grow from the ground.

* Animals: These were characterized by their ability to move and their need for food.

While Aristotle's system was a significant step forward in organizing the natural world, it was relatively simple and lacked the sophistication of later systems.