What did Shakespeare praise through sonnets?

Most of the recognized sonnets (1592~ 1598) are written to a young aristocrat, and the other group of poems is written to a woman with dark skin. These poems praise friendship and love, and poets regard them as symbols of harmonious relations between people. He particularly emphasized the humanistic ideal of spiritual combination, loyalty and understanding. The poet praises youth and beauty to contrast with ugliness in reality, and firmly believes that beautiful things should last forever and can be immortal with the help of literature and art. The poem also shows the poet's criticism of reality and life experience.