K.C. Bhattacharya, a noted Indian Philosopher, insists on speakability as a necessary character of Philosophy. According to him, it is a must. It cannot be understood unless expressed. It implies that Philosophy is meant to be communicated to others. It is to share the Philosophical Knowledge if not Wisdom. Others are recipients. So, Philosophy is for Others.
The Philosophy conveyed is often developed by Others. We are just the transmitters. We understand a philosopher and share our understanding with Others but cannot claim any credit if the philosophical ideas conveyed are crystallized by others.
Philosophy for Others reveals the purpose whereas Philosophy by Others explains the doer. If it is God-given Philosophy, the Other is God, Infinite, Eternal Spirit, the Transcendent ground of all existents.
The more we study Philosophy, the more it becomes clear that what is most important is neither Philosophy for Others nor Philosophy by Others but Philosophy of Others.
It refers to our view, perception, conviction, attitude, approach to Others. Everything that exists(and even does not exist) other than myself is regarded as the Other.
How is the Other viewed? Different Philosophers have propounded different theories ranging from sheer hostility to essential non-duality. In simple words, there are philosophies holding that it is simply impossible to attain harmonious relationships as each individual is unique. On the other hand, we do have philosophies upholding the idea that all is essentially One- The manifestations may be different but the core is one and the same. There are Others, like Buber, who have maintained the oscillations from I-it to I-Thou relations with others as fundamental reality.
Of course, the Golden Mean is also preached. I am different from Others but it is better in the interest of ALL to work in a common direction towards the shared ideal or Ideal.