grammar - Flipping Sentences and Verb Agreement

Is the following sentence grammatically correct in regards subject-verb agreement?

One of the main facets of the soul is the feelings humans treasure
above all: love and compassion.

The sentence seems to retain its meaning when flipped around, revealing that "the feelings" might be the true subject, and indicating that the verb form "is" could be incorrect. For example:

The feelings humans treasure above all -- love and compassion -- are one of the main facets of the soul.

Answer

Yes. What you are referring to is called subject-complement agreement. When you have a subject and complement that differ in number, the conjugation of the verb is determined by the number of the subject, not the complement.

Example 1:

• One of the things is feelings. ("One" - singular subject; "is" - third-person singular)


• Feelings are one of the things. ("Feelings" - plural subject; "are" - third-person plural)

Example 2:

• The States are the Union.


• The Union is the States.

Example 3:

• John and Jack are the first team to arrive.


• The first team to arrive is John and Jack.