While discussing the formation of mountains, he explained: Philosophy of science In the Al-Burhan (On Demonstration) section of The Book of Healing, Avicenna discussed the philosophy of science and described an early scientific method of inquiry. He discussed Aristotle's Posterior Analytics and significantly diverged from it on several points. Avicenna discussed the issue of a proper methodology for scientific inquiry and the question of "How does one acquire the first principles of a science?" He asked how a scientist would arrive at "the initial axioms or hypotheses of a deductive science without inferring them from some more basic premises?" He explained that the ideal situation is when one grasps that a "relation holds between the terms, which would allow for absolute, universal certainty". Avicenna then added two further methods for arriving at the first principles: the ancient Aristotelian method of induction (istiqra), and the method of examination and experimentation (tajriba). Avicenna criticized Aristotelian induction, arguing that "it does not lead to the absolute, universal, and certain premises that it purports to provide." In its place, he developed a "method of experimentation as a means for scientific inquiry." Logic An early formal system of temporal logic was studied by Avicenna. Although he did not develop a real theory of temporal propositions, he did study the relationship between temporalis and the implication. Avicenna's work was further developed by Najm al-Dīn al-Qazwīnī al-Kātibī and became the dominant system of Islamic logic until modern times. Avicennian logic also influenced several early European logicians such as Albertus Magnus and William of Ockham. Avicenna endorsed the law of non-contradiction proposed by Aristotle, that a fact could not be both true and false at the same time and in the same sense of the terminology used. He stated, "Anyone who denies the law of non-contradiction should be beaten and burned until he admits that to be beaten is not the same as not to be beaten, and to be burned is not the same as not to be burned." Physics In mechanics, Avicenna, in The Book of Healing, developed a theory of motion, in which he made a distinction between the inclination (tendency to motion) and force of a projectile, and concluded that motion was a result of an inclination (mayl) transferred to the projectile by the thrower, and that projectile motion in a vacuum would not cease. He viewed inclination as a permanent force whose effect