Breaking down the question
The phrasing how do you justify asks you to defend, at least in part, Dumont's methodological choice — his deliberate decision to treat caste as an ideology organised around the opposition of the pure and the impure. The examiner recognises this produced an intellectualised, that is abstract and cognitive, account of Indian society, and wants you to explain why Dumont made that choice and whether it can be defended.
A good answer both justifies the approach and acknowledges the well-known objections, so that the defence is critical rather than uncritical.
How to approach it
Set out what Dumont means by ideology and why he prioritised it in Homo Hierarchicus. Explain the structural logic — the value opposition of purity and pollution and the encompassing of the contrary — and show what this made visible.
Then justify the stress on ideology by contrasting it with purely empirical or materialist readings, before conceding the criticisms of Berreman, Gupta and others. Use perspectives on caste for the comparative frame.
Model answer
For Louis Dumont, caste could only be understood as a system of ideas and values — an ideology — rather than as a collection of empirical groups or a mere distribution of power. In Homo Hierarchicus he argued that the single value organising the whole is the opposition between the pure and the impure, from which the ranking of castes logically follows. His method is structuralist and comparative — he read Indian society as holistic, subordinating the individual to the whole, and defined it against the individualism of the modern West.
This deliberate stress on ideology can be justified on several grounds. First, it grasps caste as a coherent totality rather than a heap of customs, revealing an underlying logic that connects seemingly disparate rules of marriage, food and occupation. Second, the concept of encompassing of the contrary explains how the status order can subordinate power — the priest ritually ranks above the king — which materialist accounts struggle to capture. Third, the comparative method illuminates what is distinctive about Indian society by holding it up against Western values.
The intellectualised character of the account is thus not an accident but the price of seeking a system's inner meaning. It offers analytical depth and coherence that empirical description cannot.
Yet the defence must be qualified. Critics such as Gerald Berreman argue that Dumont ignored the lived experience and resentment of the lower castes and mistook the Brahminical view for the whole. Dipankar Gupta contends that caste rests on multiple ideologies and cannot be reduced to a single purity axis, and that power and material interest are underplayed. Dumont's textual, book-view bias neglects the field view.
On balance, the stress on ideology is justified as a method that reveals the cognitive architecture of caste, provided it is supplemented by attention to power, dissent and empirical variation.
Examiner's perspective
The examiner wants a defence that is genuinely argued, not a summary. Strong answers explain why an ideological reading yields coherence and captures the status-power distinction, using terms such as encompassing of the contrary accurately. They then temper the justification with Berreman's field-view critique and Gupta's plural-ideology argument. Balancing justification with critique, and citing Dumont's own concepts precisely, secures the top band.