The next chapter deals with the idea of Tradition from the viewpoint of perennial philosophy, defining it as "truths or principles of a divine origin, revealed or unveiled to mankind... through various figures envisaged as messengers, prophets, avataras, the Logos, or other transmitting agencies, along with all the ramifications and applications of these principles in different realms, including law and social structure, art, symbolism, the sciences, and embracing of course Supreme Knowledge along with the means of its attainment.

In the following chapter, Nasr develops his notion of scientia sacra, defining it as “that sacred knowledge which lies at the heart of every revelation”.

According to Nasr, realized knowledge "concerns not only the intelligence but also the will and the whole psyche", and its attainment “requires the acquisition of spiritual virtues, which is the manner in which man participates in that truth which is itself suprahuman”.

[17] In the volume of the Library of Living Philosophers devoted to Nasr's life and thought, Wolfgang Smith writes: "For the first time in modern history, I would venture to say, the undistorted and unadulterated voice of the perennial and universal tradition could be heard within the prestigious halls of academe.

According to Ioan Petru Culianu, the thesis it relies on "cannot be validated (or falsified) in any way," adding that it is "meant for a pious public already convinced of the truth and importance of Nasr's message" and that "it remains a conviction only for those of us who are not spoiled by “rationalism and empiricism” to such an extent as to need some form of demonstration.

Regardless of what one’s reaction to these lectures may be, they constitute without question a learned and eloquent vindication and apology for a point of view that has long been in disfavor.

"[19] Adnan Aslan echoed the same view, saying that "This magnum opus when properly understood and assimilated, is indeed able to evoke an intellectual transformation.

Looking back on Knowledge and the Sacred, intellectual historians may one day rank it with William of Moerbeke's Latin translations of Aristotle in the thirteenth century, Marsiglio Ficino's of Plato in the fifteenth, or D.T.

[20]Gai Eaton, in a similar vein, writes: Seyyed Hossein Nasr has presented, eloquently and against a background of great erudition, the stark contrast between, on the one hand, the traditional view of the nature of things and of man’s destiny and, on the other, the secular fragmented ideologies current in our time.

[21]Victor Danner writes in a review of the book that "It is a work with magnificent sweep both in a philosophical and historical sense, revealing a universality of thought that only a handful of contemporary thinkers of the East or the West have mastered".

[22] According to Gerald Largo, Nasr "has contributed an indispensable unified effort to retrieve the sapiential perspective which he articulates so brilliantly and clearly.