@Didymos Thomas,
It's interesting how the majority believes working that 9-5 job sitting in that cubicle is what humans are *supposed* to be doing. Or, if we can't actually apply philosophy to our 'normal' lives, it's not practical? Practical according to what? We must remember that these working lives, the economies across the world, the buildings we see, the organizations we join, this whole concept of a 'normal' life, WE have constructed. It's a supreme flaw to not consider, to not consider that there are many ways to live a life, and life does not have to be like the one we've constructed and have been raised to believe. Some philosophers have ventured to the great ends of the globe in order to separate themselves from active society and have lived lives of contemplation. And though I'm not saying that this is the path we should all take, we must remember that there is more to life than that 9-5 job, or that house we come home to. We cannot say philosophy isn't practical for everyone, because we cannot judge another's life, we cannot judge what they want out of their existence.
Ultimately, it seems your father has good intentions and wants you to have a nice, successful life, however, he's not considering things. If contemplation brings you happiness, if it fulfills you, then I say GO FOR IT. Don't let anything hold you back. Enjoy your life as you see fit. Sure, everyone is strapped to a ball and chain to an extent, but there are ways around - you just have to find them. You must explain to your father your true feelings regarding the matter, and not a recited argument for the study of philosophy. Tell him how you feel, not what you think. It will take time, but be patient. Try to be as understanding as possible, and don't hold him in a negative light. Remember, he believes he has your best interests at heart and loves you. Show him understanding, and be mature in the way you present all of this. He will either realize that he should allow you to reach your own happiness, or he will be stuck believing his path is the only way. That's out of your power, but you must at least give him the knowledge so he has an opportunity to understand.
Take care, and good luck.