I have extracted the following sentences because I don't conjecture the meaning of the word 'for' used in these at all, so ask you helpers for help.
[Poets are concerned with people and with life, and they use the medium of poetry to communicate their understandings and the truths of life as they see them. They try to give us the "feel of the idea" and the "experience beneath the idea." They interpret the innermost spirit of a people, of a country, of a civilization;
for poetry is a revelation or an interpretation of life in some of its aspects.
]I'd like to know what meaning dose the word 'for' in bold have.
Thank you in advance for your help.