Casibjorn asked:

They say that Plato said everything in Philosophy and everything that follows is but a reflection of
what he has written. Currently I'm a student in the Philippines and a seminarian, and I am questioning
about the existence of extra-terrestrial life. In cosmology as well as in metaphysics this question is
raised but I need a second opinion, especially from a true philosopher not just a master.

Hoping you will answer, God bless and peace.

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It was the metaphysician Alfred North Whitehead who said:

The safest general characterization of the European philosophical tradition is that it consists of a
series of footnotes to Plato. I do not mean the systematic scheme of thought which scholars have
doubtfully extracted from his writings. I allude to the wealth of general ideas scattered through them...

Process and RealityCorrected Edn Macmillan 1978 p. 39

Here is Plato's view on extra-terrestrial life:

Are we right in saying that there is one world, or that they are many and infinite? There must be one
only, if the created copy is to accord with the original. For that which includes all other intelligible
creatures cannot have a second or companion; in that case there would be need of another living
being which would include both, and of which they would be parts, and the likeness would be more
truly said to resemble not them, but that other which included them. In order then that the world might
be solitary, like the perfect animal, the creator made not two worlds or an infinite number of them; but
there is and ever will be one only-begotten and created heaven.

Plato Timaeustranslated by Benjamin Jowett

I wonder whether it is this passage that has inspired your question?

Well, isthere life on Mars? Or if not on Mars, somewhere in the wide universe? It is difficult to
conceive how there can be a logicalreason why there cannot be other worlds inhabited with
intelligent life, even on the assumption of a Creator. If an artist paints the perfect painting, then
perhaps he has no need to ever paint again. But we cannot reliably second-guess God's purposes.

The alternative is to go for the best theory. At the present time, there is a massive project underway
to try to detect radio transmissions that might have emanated from extra-terrestrial life. The lack of
positive results may only be an indication that intelligent life is not very common in the universe. So
the question comes down to probabilities. Assume such-and-such as the probability that intelligent life
evolves on Earth. Estimate the total number of planets in the universe where life had the chance to
evolve, do a simple calculation and out comes the answer.

I am naturally curious to know whether there are others, somewhere, like us. Until we actually meet
up with creatures from another planet, however, the answer is not a foregone conclusion. It is still
possible that the initial probability of intelligent life evolving on an Earth-like planet, is much, much
lower than the current estimate. In other words, it is possible that we are, indeed alone.

Geoffrey Klempner