An optimist says determinism may or may not be true, but the concepts, they know, have genuine application and justified practices. According to the optimist, the application has an "adequate basis", therefore, it makes no difference to whether or not determinism is true or false. Optimists believe a person's behavior are effected from socially desirable ways. Which effects them bringing about peaceful productive and socially desirable interpersonal interactions, which does not imply determinism to be false. Knowing what you are doing is having freedom, which means they chose to do what they are doing and know what they are doing, implying that determinism is false. Overall, optimists believe determinism is false.
On the other hand, a pessimist says that if determinism is true then these concepts and practices have no application and are not justified. From a pessimist's view point the concepts of moral obligation and responsibility have justified application to people and their actions, which means if people act freely because they are not determined to act as they do. The person could have done the complete opposite, which makes determinism false. But if determinism is true, both obligation and responsibility have no application to anything. Justified application of the concepts of moral obligation and responsibility requires freedom, and freedom implies the falsity of determinism. In conclusion, a pessimist believe determinism is true.
There are still people who do not know the thesis of determinism. It all depends on how one