If we believe salvation comes by grace, without any work on our part, it's only logical that it can come even at infancy, so babies should be baptized. It's certain that our enemy would not wait to attack young children, so having them brought into the grace of our Lord Jesus Christ early is an advantage for them. They will have to exercise free will to remain in Christ as they age, but their intellectual understanding is not required for them to be in Christ. Entire families where baptized according to Acts, with no mention of those family members who could intellectually grasp God's grace.
Basil