The comparative study between Kant and Thomas Aquinas regarding the limitations of metaphysical knowledge, yields notable coincidences, despite the clear differences between the systematic approach of each thinker. This makes it possible to appreciate in a better way the core of the question, and perhaps provides some help in the clarification of matters concerning the value of metaphysical knowledge. Despite appearances, our approach is not primarily historical, but systematic-philosophical. The cited authors will be used to the study a philosophical problem, (...) and not as authority arguments. For that reason, we will confine ourselves to primary sources, without resorting to historical studies save for dispelling exegetical doubts or confirming the author’s assertions. (shrink)