Choose the one word substitution for the following description: The philosophy of putting another's welfare above one's own.

Introduction / Context:
This question tests your knowledge of philosophical and ethical terminology. The description refers to a moral attitude or philosophy concerned with prioritising the welfare of others over one's own interests. Understanding such terms is useful in ethics, sociology, and general English vocabulary.

Given Data / Assumptions:
- Description: The philosophy of putting another's welfare above one's own. - Options: Agnosticism, Polytheism, Altruism, Iconoclasm. - The focus is on concern for others rather than belief in gods or opposition to traditions.

Concept / Approach:
Altruism is the principle or practice of unselfish concern for the well being of others. An altruistic person acts to benefit others, often at personal cost. The other options relate to religious belief or to opposition to established images and traditions. By matching the idea of prioritising another's welfare with these definitions, we arrive at altruism as the only suitable term.

Step-by-Step Solution:
Step 1: Recognise that the description emphasises putting another person's welfare above one's own. Step 2: Recall that altruism refers to selfless concern for the good of others. Step 3: Consider agnosticism, which refers to uncertainty about the existence of God and is unrelated to selflessness. Step 4: Consider polytheism, the belief in many gods, which again has nothing to do with prioritising others. Step 5: Consider iconoclasm, which involves attacking or rejecting cherished beliefs or institutions, not caring for others above oneself. Step 6: Only altruism expresses the philosophy described in the question.

Verification / Alternative check:
Look at example sentences: Her decision to donate most of her income to charity is a remarkable display of altruism. This clearly shows a person putting others' needs before her own. This usage matches the description exactly. In contrast, you would never use agnosticism, polytheism, or iconoclasm in such a sentence, which confirms that they belong to different conceptual categories.

Why Other Options Are Wrong:
Agnosticism concerns belief about knowledge of God or the supernatural and says nothing about caring for others. Polytheism is about believing in many gods and does not describe any particular stance toward other people's welfare. Iconoclasm refers to attacking established beliefs or symbols and is not linked directly to selflessness or self sacrifice.

Common Pitfalls:
Learners may confuse altruism with similar sounding or equally abstract terms. To avoid this, connect altruism with the idea of alter, meaning other, and remember that it is about making others' well being a priority. Keeping simple example sentences in mind, like altruistic acts of charity, can help you recall the correct term during exams.

Final Answer:
The correct one word substitution is Altruism.