Core Legal Answer & Context: Substantive equality moves beyond formal equality (treating everyone identically) to address historical and systemic disadvantages. It recognizes that identical treatment can perpetuate inequality if it ignores existing disparities. The goal is to achieve equality of outcome or opportunity by providing differential treatment where necessary, often through affirmative action or special provisions for disadvantaged groups. This approach aims to level the playing field by acknowledging that people start from different positions.

Relevant Statutes and Sections: Indian Constitution: Articles 14 (Equality before law), 15 (Prohibition of discrimination), and 16 (Equality of opportunity in public employment), particularly clauses 15(3), 15(4), 15(5), 16(4), 16(4A), 16(4B) which permit special provisions for women, children, and socially/educationally backward classes.

Important Landmark Cases:

1. State of Kerala v. N.M. Thomas (1976): The Supreme Court held that Article 16(4) is not an exception to 16(1) but an emphatic way of stating the principle of equality. It recognized that equality of opportunity means effective equality, allowing for compensatory discrimination.
2. Indra Sawhney v. Union of India (1992): This landmark 'Mandal Commission' case upheld the constitutionality of reservations for OBCs, reinforcing the concept of substantive equality as a means to achieve social justice.

Clear Conclusion: Substantive equality is a dynamic concept essential for achieving true social justice. It mandates that the state take proactive measures to eliminate existing inequalities, ensuring that all individuals, despite their differing starting points, have a genuine opportunity to thrive.