At first, Jonas sees the logic in sameness. It is even a source of concern for him, at times, that he is one of the few people in the community with light eyes instead of dark ones. He sees that with sameness, there isn't competition over appearance, or any other issues that cause conflict. However, as he begins to feel the depth of the various emotions in the memories, and he begins to see colors and things from the outside world, he realizes that diversity is important. He understands that being unique isn't bad, it's actually good.
An example of this is illustrated in Jonas's opinions on releasing. At first, when he doesn't know the true nature of the release, he thinks that anyone who doesn't fit in with the sameness of his community can go and live somewhere else where their personality will be more suited to the personalities of the other people in their new community. He believes that sameness helps people get along with one another, and that releasing someone who is different is actually helping that person find friendships and connections elsewhere. Once he realizes that the release is actually a lethal injection, he begins to understand that part of the reason people are released is because they do not fit in. Anyone who does not fit in, or presents an abnormality, is killed (like Rosemary or the twin baby his father releases). He realizes then that the community controls the sameness with lethal force, and he questions the cost of this sameness.