What is the world? Does it really exist like I see it, or is it 'all in my head'?
Here, 'the world' means the entire universe - space, time, matter, energy, galaxies, stars, planets (including Earth), life (including human beings) and so on.
Most likely you believe that there is a real world out there and you are part of it. It existed before you were born and it will continue to exist after you die. But some people question all of this and they have other beliefs. Maybe the world doesn't really exist and you are just dreaming it, in which case you may at some point wake up from that dream and experience reality as it is. For some people it's important that the only world that we can know is what our mind and brain create from our senses - what we see, hear, smell, taste and feel.
Now spend as much time as you wish thinking about your beliefs on this matter. You don't have to spend just one session on this: your thoughts may return to the subject in those idle moments in the day when you are not thinking of anything in particular; you may be surprised by what comes up at such times. Jot down some notes if it helps.
In Part 5 you will be thinking about how you believe the world was created. It probably makes things clearer for you to wait until Part 5 to record your religious or scientific beliefs about how the world came about.
It may be that you don't have any particular beliefs about these matters and they don't play a part in your personal philosophy. This is absolutely OK and you can make this clear when you write this up.
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Some possible beliefs are given below, but they are only suggestions to help you. You are not being asked to choose any of them and your beliefs might not appear here. However, if you do find that one of them describes your beliefs, please feel free to put it in your own words.
Probably most people believe that the world 'out there', the world that they see, hear, feel, smell and taste is real and they are a part of it. So the world would still exist if they didn't - say before they were born or after they have died.
You may believe that it's important to add to this that the only world you can know is what your mind creates from your senses - what you see, hear, feel, smell and touch. However, this is still a true picture of the real world. Alternatively, you may believe that the world in reality may be very different from the world created by your mind.
Some people believe that all that exists in the world is 'me' - i.e. themselves. So, you may believe that everything else apart from you, including other people, is created by your mind, like 'virtual reality' or a dream you are having. Or you may believe that other people exist but, like yourself, the world for them is created entirely by their mind, again like a dream they are having.
You may feel too unsure about what is real and exists. Perhaps you are still thinking about it and have yet to make up your mind. Or maybe this is not something that you think about; maybe you believe that, since we will never know the answers to these questions, they don't matter to you. It is absolutely fine to put either of these in My Personal Philosophy.
When you are ready, begin writing up your beliefs under the heading 'What I believe about reality' in your 'My Personal Philosophy' document.
When you have written as much as you wish, and when you are ready to resume, return to 'Part 3: Setting Off' and choose your next part. You may find that Part 5, concerning your beliefs about the origin of the world and life, follow naturally from here.