The Logics according to Aristotle is "Instrument" or "organon" of science, as every sciense is a graund on the basis of causing reasons, and logics studies the forms of right thought, outcoming and conclusions.

Petritsi wants by the help of laws of logics to ground the reality of the one, as the first beginning. Besides, his aim is to find aut interdirection of the one and multification. This is a question of our reality, about the explaination of the diversity of our surrounding world.

The objective of our work is to show the use of laws and rules of that logics by Petritsi for achievement of his goals, that is offered by Aristotle or more concretely the ontologic justification by the forms of conclusion and outcoming.