Many people reject the death penalty on the grounds of mistakenly taking the life of an innocent person. Why then do we allow abortion? If no one is certain when life begins, isn't to accept abortion an acceptance of mistakenly taking the life of a person?

Does the study or the practice of Social Work raise interesting philosophical questions? If it does, would these questions be placed only in branches "more practical" like political philosophy and ethics, or also in branches "less practical" like epistemology and philosophy of science? There could be a "philosophy of social work", or would it have to be a smaller point in other discipline?

Karl Marx based his claim that all workers are exploited within capitalism, upon the assumption that the value of a product is basically determined by the amount of labour put into it. More specifically, the value of a product equals the cost of raw materials, usage of means of production (both factors are more or less constant) and then extra value added to it because of labour (e.g. coffee is worth more than the mere sum of water and coffee beans; the extra value is created by grinding the beans, ...) The point then is that a worker's wages are typically less than the extra value of the product added by labour. Hence the worker is performing some of the labour for free, hence exploitation. Now my question: I can see the reasoning behind this, but I question the assumption that the value of the product is determined by the amount of labour put into it. For example, suppose one worker is digging for gold, while another one is digging for stone. Let's say the labour they do is roughly comparable, yet...

Does a person have any moral/legal OBLIGATION to have sex with his/her partner in a relation of marriage? Thanks.

I have heard that Descartes' "cogito ergo sum," while intuitively compelling, is actually a logically flawed argument. Can someone explain how/why it is logically flawed? I have heard the argument that anything that has any properties at all has the property of existence automatically, so existence is not a substantive property (have I put that correctly?). Even if that is true, why should it matter so as to make the cogito argument flawed? And are there any other, perhaps better logical arguments against Descartes' proposition?

Anyone presently in college probably knows students who have take drugs like Adderall to help them study (I should add that whether all of these actually suffer from ADD is often doubtful). Should this be considered unethical? There's an obvious comparison between drug-use of this sort and steroid-use in professional sports, but I've always been suspicious of this analogy.

We are often told that beauty is in the eye of the beholder. But I wonder if this is not an over-simplification. Surely some things are beautiful regardless of our response to that beauty. Is there not a case to be made for completely objective beauty?

Do I need to have a 'greater authority' to know that murder is wrong? I don't believe in god. But I believe that murder is wrong. What is my logical reason to hold to rules that I don't 'need' to be bound to?

The concept of a homunculus suggests that there is an inner core in each of us, a "self" that makes functional and moral decisions. The emerging sciences of complex adaptive theory and network theory suggest there is no homunculus in complex living systems (from cells to the global economy). An identifiable self has not been located by neurobiologists and may never be located. The self appears to be a composite of many internal systems that interact with many external systems. If we cannot locate the self, if there is no homunculus to point to as the agent of a "good" or "bad" decision, if people are more than the sum total of their parts and cannot be reduced to a single part (such as the self), does morality still exist? That is, does the concept of morality exists if there is no concept of the self?

I am a philosophy student and I have noticed that there are some days (rarely) in which I simply can not absorb. A lot of times I will work extra hard to concentrate but find that it is simply useless and a waste of times. Is it necessary to take breaks from intellectual work? I always just assumed the mind could handle whatever you could feed it, is this false? Are there things in which I can do to improve my concentration and productivity in situations like this? Or do I just need to slow down? Thanks, Josh