A long time ago I participated in a discussion at Dr. Feser's blog. Although this discussion was chiefly distinguished by a presentation of my clearly brilliant but, alas, sadly neglected solution to the Orcish Souls Problem (OSP), the "Ainur-Latin Averroist Hypothesis" (clearly applicable also to respective problems concerning trolls and giant spiders), at some point we exchanged comments with --the- Daniel concerning the drive towards transcendence, which I agree is (arguendo, at least as a result of some examinations) recognisably present in many cultures, the Christian response that suggests itself immediately - that the Holy Spirit breatheth where he will - not being deemed quite satisfying by the non-Christian party of the conversation. I believe what follows can be of some interest to him and perhaps others, though as a Trinitarian I do not mean to present this as a substitution of any kind, and will hopefully even raise the plausibility of the Faith.

In an ethics (moral philosophy) manual written by a middle-20th century German Benedictine (which I do not happen to have at hand, unfortunately, and thus it is to remain unnamed at least for a time) I discovered something which stroke me as odd: a discussion of natural happiness. Not that this is not a common item in Thomistic works. The remarkable feature that had previously escaped my attention was that posited a distinction between imperfect (attainable while alilve) and perfect natural happiness (reserved for the dead). Given that the same theme is elaborated in greater detail in the work of Fr. Matthias Scheeben called "Nature and Grace" (Natur und Gnade, Matthias Joseph Scheeben, Gesammelte Schriften, Band 1, 1941, Freiburg im Breisgau Herder & Co. G.m.b.h.) that I have at hand, I will be relying on it for a general exposition.

The object of the book is to carefully and consequently distinguish between the orders of grace and nature and to crown the effort with an exposition of the true doctrine. Fr. Scheeben sets himself in opposition to what he sees as 'polar' errors of some of the (supposed) Augustinian revivalists and Rationalists (in terms of 19th century Catholic discussion), the error being the exaggeration of the proper area of grace and nature respectively.

According to the view defended (which I find eminently plausible), our mortality, the necessity to conquer the passions and to strive to progress in virtue are to be accepted as flowing from our nature as rational animals (even, say, old age has its utilities in this quest: as, ceteris paribus, old humans are relatively less vulnerable to the attacks of the passions and are normally presented with an opportunity to consider their life, creation and divinity).The imperfect natural happiness in this life is to bind oneself to God through knowing and loving Him, as well as cultivating moral relations to God, one's neighbour and the passions. 
The perfect natural happiness is only acquirable after death. The separated soul is said to be able to see itself directly upon separation from the body, this sight becoming first available after sensory input is no longer there. A separated soul of a virtious man will recognise in itself (the most perfect created reality naturally accessible by humans), made clearer by virtue, a certain image and likeness of God, and the degree of this unending contemplation and corresponding joy will depend on the rectitude of the will. Presumably, relatively vicious souls would suffer due to the inability to attain this contemplation and the deformity introduced by their vices. 

As the natural state does not imply any direct vision of God as its goal, it is identified as "servitude": God is our master and benefactor, as opposed to the directness and intimacy meant by the order of grace, which makes us partakers of Divine Life and converts mere servants into God's adopted children. 

If this is correct, can we not expect our life, due at least to our bodily constitution to somehow prod us into the realisation that this life is even naturally a voyage? 

I've also found something similar in a work by Brentano (in German, and unfortunately also not at hand). 
Perhaps all of this will be news to no one, or even universally written about, but a discovery that I've somehow managed to fail to notice all of this in Garrigou-Lagrange and others would greatly amuse me.