What are the differences between Hinduism and Sanatana Dharma?

Hinduism, more accurately referred to as Sanātana Dharma, is said to have originated in the Indian subcontinent over 5000 years ago. The term Hindu was a misnomer used for the people who lived beyond the Sindhu River, ie residents of the Indian subcontinent.

Hinduism is not a religion like Islam, Christianity or Judaism.

HINDU-ism

In English Language ‘ism’ signifies a particular and somewhat singular idea or belief. Communism, vegetarianism, pacifism, consumerism, ethnocentrism. All these words lead back to believing or following a particular idea.

The word Hindu has been used meaning Indian, until the suffix ism was attached by the British in the 19th century.

Almost immediately, the West shifted the meaning of Hindu away from it geographical identity and towards a particular and singular religious identity, which in the post-enlightenment West meant a belief, a doctrine.

Even the Imam Bukhari of Jama Masjid in Delhi has described how he was registered at the gate of Mecca during his Haj as a Hindu Muslim, not for a second considering the word Hindu to be anything other than a geographical signifier.

The British added the ism to Hindu as a means of representing the Hindu, homogenizing, standardizing, and reducing the Hindu to a defined set of beliefs (the doctrine), defined scriptures (the text), and deity (measured against a monotheistic standard). And thus, Hinduism, as defined by the British and others (certainly with a great deal of Indian indigenous read Brahmin input), could comfortably fit within the Euro post-enlightenment categories, and on the Imperial grid of all things.

SANATHAN DHARMA

Sanatana means eternal, never beginning nor ending.
 Dharma is from dhri, meaning to hold together, to sustain.

The Sanatan Dharma, on the other hand, is not overly concerned with ideas and belief. Traditionally Sanatan Dharma signifies the dynamic sum of ALL the knowledge of ALL the diverse traditions of Greater Hindusthan, if you will, since the beginning of time.

It is not the SUBJECT of knowledge (or the means by which it may be obtained – as in an ism), but the OBJECT of knowledge. It is not something one man or woman can put their hands around, or know or master in a lifetime. There are no ideas I know of that address the Sanatan Dharma as a whole, but rather interpretations and commentaries of small parts of it. Even the word dharma is used today very largely within the framework of the European post-enlightenment category of religion, while, actually, traditional people think of dharma much in the same way modern people think of science.

The uniformity and obedience to doctrine that the monotheist religions(Christianity, Islam, Judaism) demand has always been conspicuously absent from Hindusthan. It is because great thinking has always been marked by great debates and commentaries, and oral tradition has avoided the rigid limitations and authority of the printed text.

Note- Hinduism as it is called today has evolved further post independence. Terms like Hindutva has emerged.

• Who or what is a Hindu? What is Hindutva, Hinduism and Sanatana Dharma? What is the difference?
• How is Sanatana Dharma different from Hinduism?

(I fail to understand why in post independence era we continue to use Hinduism instead of Sanatana Dharma?)

(I am a Catholic hence the answer may have flows)