I use Humes idea about the 'is..ought to gap' (or my spin on it) mainly to make sure I have good reasons for what I do -and what I advise others to do- and to make sure actions are not based purely on cultural pressures or recklessly induced policies. I don't use it much to judge whether the actions are morally right or wrong but whether we rationally have good reasons for doing or not doing something based on our present knowledge and feelings.
Since the introduction of neuroscience I have seen many attempts to bridge the 'is..ought to gap' with facts; especially with facts about what makes us feel better or worse. By seeing more and more respected people claiming that they bridged the is..ought to gab and that the is..ought to gap is a myth I naturally have started to question whether I am wrong to use it THE WAY I USE IT.
The argument goes something like: if we can confirm that a specific action consistently lead to a specific chemical reaction in the test subject's brain and if this chemical always makes the test subjects feel good, then we can conclude that this is what we 'ought to' do, regardless of what anyone value.
Another version is similar but is based on survival i.e. that if it helps us survive or live longer then that is what we ought to do.
Both of these arguments claim to produce logical 'ought to' conclusions without using values. I welcome these studies and think we can learn a lot from them i.e. they can help us get ever closer to objective values (values we all agree from our subjective views are good or bad). But I don't think they bridge the 'is..ought to gap' for at least two reasons: Firstly, because (in the first case) you are implicitly saying that you value feeling good in the particular way the chemicals make you feel, and in the other case you are implicitly saying that you value to live longer. Secondly, because there are plenty of times when you value some other chemical even more (even if it might be true that you as a human always value feeling good in the particular way that chemical make you feel), and there are plenty of times when you value doing something dangerous or unhealthy over living longer. Therefore you can not use even what is objectively valuable (assuming for the sake of argument there are such values) alone to decide what you 'ought to' do. You still have the evaluate each unique situation; you have to 'look inside' and out of all the alternative consequences you can imagine you have to choose what you value most right now before you can decide what you 'ought to' do.
Does anyone know a strong case against the fact that 'in order to rationally justify an ought to (i.e. what you should or should not do) I have to present a value'? Or Should I embrace the 'is..ought to gap' if I value having rational reasons for the rules and guidelines I put up for myself and others?
ps. I'm not interested in the argument that 'I have a goal' (i.e. a fact) therefore 'I ought to do x'. Since having a goal means (to me) that I have a value i.e. it might be a fact that I have a goal (or even other types of values) but this goal is then a implicitly saying that 'I value...'. Therefore this argument does not bridge the 'is..ought to gap' without a value.
Definition background (how I define/understand value):
I use both value and desires to mean 'what is compelling to me'. I often separate them in that my desires are my subconscious (irrational) and may values are my conscious (rational) compulsions. But this separation is often useless since few people use it. So to me it make sense to say that I can potentially prove what someone value/desire by seeing what they do but I have only proven what they subconsciously value/desire right now; your rational values/desires have to come from a conscious evaluation in your mind. So you can value one thing but do another and therefore states of affairs can teach you that your subconscious desires are not in accordance with your conscious desires, but ultimately it is up to you whether you decide to leave them like that, reprogram you subconscious desires or change you conscious values.