“The actual is the possible in so far as it is determined.”

Simplified Meaning:

When we talk about something being "actual," we are referring to what is real and happening right now. "Possible" means what could happen or what can be done in the future. The phrase means that what is real and happening now is actually one way that things could have possibly turned out, but it became real because certain choices or actions made it happen that way. Think of a tree growing from a seed. There are many ways the tree could grow—tall, short, strong, weak—but the way it actually grows depends on things like sunlight, water, and soil. If you water the tree and give it lots of sunlight, it will grow tall and strong. So, the actual tall, strong tree is one possible outcome that became real because of the care it received. In your own life, this idea can show you that your actions shape your reality. If you work hard and make good choices, you turn the possible future you want into your actual life. For example, studying every day makes passing a test an actual result. Thus, your current reality is a result of the determined efforts and choices you make.