In his Repastinatio. . . Lorenzo Valla launched a heavy attack on Aristotelian-scholastic thought. While most of this book is devoted to metaphysics, language and argumentation, Valla also incorporates chapters on the soul and natural philosophy. Using as criteria good Latin, common sense and common observation, he rejected much of standard Aristotelian teaching on the soul, replacing the hylopmorphic account of the scholastics by an Augustinian one. In this article his arguments on the soul's autonomy, nobility and independency from the body are studied and analysed. His critique of Aristotle's opinions on natural phenomena as being untrue to what we observe will also be briefly studied. His arguments do not show him always to be deep or consistent thinker, but the critical review of Aristotelian philosophy proceeds from some philosophically interesting assumptions. Moreover, from a broader historical perspective his undermining of Aristotle's authority may be regarded as a contribution to the final demise of the Aristotelian paradigm, even though the humanist critique was just one factor in this process.