Jan Łukasiewicz distinguished three various formulations of the law of contradiction in Aristotle's considerations concerning axiomatic foundations of philosophia prima in the book Γ of Methaphysics. Łukasiewicz referred to these formulations as „ontological”, „logical”, and „psychological”, respectively. The author focuses his attention on the last of them, namely to the so called psychological approach. He finds this approach to be an inadequate interpretation of Aristotle's views and tries to show that the most appropriate interpretation is pragmatic-logical.