Nothing serveS to bind Chinese across the world closer than their shared admiration of Sun Yat-sen, the founding father of modern China.

Chinese from across the world marked Sun’s 150th birthday on November 11 by paying homage to the revolutionary who led the fight to overthrow the Qing dynasty and end imperial rule in the 1911 revolution.

Tug of war over China’s founding father Sun Yat-sen as Communist Party celebrates his legacy

Despite being bitter foes for nearly a century, the mainland’s ruling Communist Party and Taiwan’s main opposition Nationalist Party, or KMT, share Sun’s aspirations for national unification and rejuvenation – two of Sun’s three main doctrines.

Sun, who founded the KMT, has been revered in Taiwan for decades as the “father of the nation” and for his devotion to national unity, improving people’s livelihoods and the development of democracy – Sun’s so-called “Three Principles of the People”.

While Taiwan’s Democratic Progressive Party, which leans towards independence, has kept a low profile regarding Sun’s anniversary, it cannot deny the fact that not only did Sun found the island’s self-ruled Republic of China – he also founded its “Five-Power Constitution”, which is based on liberal Western ideals of democracy, human rights and division of powers.

Hong Kong Philharmonic ‘awkwardly’ out of tune in debate over legacy of ‘father of modern China’ Sun Yat-sen

Communist leaders on the mainland view Sun as a proto-revolutionary – in a lengthy speech to mark the anniversary, President Xi Jinping ( 習近平 ) said party leaders were the “firmest supporters, most loyal collaborators and most faithful successors of Sun’s revolutionary undertakings”.

Xi highlighted this shared heritage this month when he met the KMT’s chairwoman, Hung Hsiu-chu.

Mainland communists and the KMT also share a link regarding Sun’s involvement in the struggles against Japanese colonial rule in Taiwan. The 1911 revolution was closely related to the outbreak of the first Sino-Japanese War in 1893 and the defeat of the Qing Dynasty which led to the cession of Taiwan.

Mainland Chinese hope Taiwan elections will revive Sun Yat-sen's spirit of democracy

However, while some of Sun’s doctrines may be cause for unity, his philosophy of rule is possibly the biggest factor dividing the major political players across the strait, irrespective of their views on national unification.

The key issue is how they work to narrow the gap in their interpretations of Sun’s “three principles”.

After decades of stellar economic growth, Taiwan and the mainland have achieved Sun’s goal of turning a stricken China into a modern nation-state.

Taiwan has also accomplished Sun’s democratic ideals as the island is now one of most dynamic free democracies in Asia following sweeping reform introduced by KMT leader Chiang Ching-kuo and his successor Lee Teng-hui in the 1980s and 1990s.

However, Sun’s ideas of democracy, freedom and human rights remain elusive on the mainland, where anything foreign or Western is squarely rejected by the ruling Communist Party, despite its avowed commitment to Sun’s political legacies.

Indeed, democracy has become the main disagreement between the Communist Party and the KMT, and the Communist Party and the DPP – a disagreement that has become more entrenched given the Communist Party’s recent revival of Maoist rule.

So if Beijing wants to narrow the political gap across the strait and realise Sun’s vision of national unity and rejuvenation, it must first show true loyalty to his philosophy of democratic reform.

Cary Huang, a senior writer with the South China Morning Post, has been a China affairs columnist since the 1990s