An aid for anyone else who found the usage "knowledges" unfamiliar and distracting:

Knowl"edge (?), n.

2. That which is or may be known; the object of an act of knowing; a cognition; -- chiefly used in the plural.

There is a great difference in the delivery of the mathematics, which are the most abstracted of knowledges. Bacon.

Knowledges is a term in frequent use by Bacon, and, though now obsolete, should be revived, as without it we are compelled to borrow "cognitions" to express its import. Sir W. Hamilton.

To use a word of Bacon's, now unfortunately obsolete, we must determine the relative value of knowledges. H. Spencer.

- Webster's 1913

I figured it was some probably-from-critical-theory-because-aren't-they-always liberal-artsism, but looks like it's just an unusual-bordering-on-archaic sense.