Yes. But first let me clarify what I mean by responsibility. It is simply the ability to respond with attention and care in an ongoing way to whatever the fates have delivered to me. Who else but I?
Did I “cause” my illness? It is possible, but very unlikely. Most illnesses are multifactorial in their causation. Genetics plays a large role in much disease. Is there any evidence that attitudes of optimism or pessimism cause conditions like cancer? Actually very little. Is there any evidence that particular attitudes more or less likely to result in cure? Actually very little.
Perhaps a better way of understanding this is to say that I am responsible for my illness in the same way that I am responsible for taking care of my children or my marriage or any other relationship I have. I should be attentive. I should be respectful. I should be kind.
I ought to pay some attention and consideration to the words of others when they point out that I may be doing things that make my condition better or worse. At the same time I shall be wary of where my information or suggestions come from. I am responsible in deciding which foods I eat. Whether it is how and where I breathe, whether it is water, plant, or animal. And perhaps most importantly the food of impressions, what sort of sensory impressions and ideas I open myself to and reflect upon.
In most religious traditions and societies there is an age of responsibility ranging from early to late adolescence when one is seen as able and expected to perform religious or social duties. The etymology of responsibility or responsible is quite interesting. The word is rooted in old French back to Latin to turn toward and hear and hear again. So there is something to the idea that one is responsible if one has heard several times the command not simply by accident.
Most importantly, if we take the idea of a colony of beings constituting the person we seem to be, we need a “responsible” self to act and “speak” with authority and maintain harmonious relationships among our many selves.