This debate is apparently based on loose terminology. Here, some definitions and ideas that might help.

**Modernity** is a period in history, which started with the _Enlightenment_ and ended around 1950, _postmodernity_ becoming right after; commonly associated with a loss of religious and moral values against individualism and scientific and technical developments. So, _Capitalism_ is debatably a consequence of it, not a cause of it, it is not Capitalism that raised a (scientifical-technical) period in history.

**Colonialism** is the practice by which a territory and a human group are subject to a foreign rule; colonialism is sometimes associated with an evolved form of animal territorial domination (cf. Fanon), which raises directly from Darwinian mechanisms. According to your friends, this is the cause of all evil; the problem is easy to solve: they can just derogate all Darwinian laws in the Congress. Oh, wait. I forget there's no universal congress. And no congress which rules animal instinctive laws (we are in part animals). And no congress that accepted Darwinian laws of evolution and survival. And no congress members proposing alternatives to the _survival of the fittest_ rule.

**Capitalism** means essentially the tendency to _accumulation of capital_, which includes the means of production, rights of ownership, free market development, natural resources, and not just that, but mainly a bunch of histories that only exist in our heads, like money, laws, power, status, etc. There is also has a good solution to this "problem", that proposed by Pol Pot, and which results are already available in history books. They can also read about Ceausescu, Mao Zedong, Stalin, Maduro, Castro, Allende, the Kim Jongs, Mariam, Hoxha, Ortega, Morales, etc. But warn them ALL cases are failures.

**Science is some type of knowledge** (that obtained according to the _Scientific Method_). **Technology** is the application of such knowledge in practice, and **Art** (not as aesthetics, but as in state-of-the-arts) is the application of those two for social benefit. 

Call this _The Natural Test_: The deepest of our instincts is to survive, and that is normally consistent with all our emotions and reason. When any living being, any individual, any human group, etc. tries a new rule, it is just tested by nature: either that being survives or not. Some specific groups that have submitted new ideas to _The Natural Test_ and ended up with huge amounts of deaths: the FARC; the Aum Shinrikyo cult; Ugandan LRA; North Korea; Jim Jones people's temple; the Khmer Rouge; Nazism, etc.

There's no point in attacking science, tech and art. Europe developed a culture for knowledge, which is a positive achievement, not a failure. Anyway, science has been always developed, all along history, in all places where humans existed. If they don't like scientific colonialism, they just need to invent the wheel from scratch, and all remaining science and technology as well.

About “colonial technology”: just ask your friends to throw their laptops, TVs and mobile phones to a river. That way, they will be getting back their sovereignty.

> Why are decolonialist attacking science and modernity?

The big philosophical issue here is _responsibility_.

By definition, any _responsible_ individual takes responsibility of what happens for himself. The responsibility to address social problems, the responsibility to solve individual and social issues. Then, he acts on it, without blaming or without complaining. For example: are there poverty issues? Ok, propose solutions without blaming others. Many organizations do so and get it successfully. Your friends need to read about _Médecins Sans Frontières_, Water.org, Acumen, Heifer, Grameen Bank, etc.

By definition, individuals which feel _non-responsible_ for what currently happens, can't take responsibility; instead, they look for blame. A lot of politicians do so. This approach produces social polarization and usually gets a lot of votes. But this approach does not propose solutions. And if they have done so, they have been submitted to _The Natural Test_ and have failed. They nevertheless insist: Pablo Iglesias (Spain), Maduro (Venezuela), Corbyn (UK), Mélenchon (La France Insoumisse), Máximo Kirschner (Argentina), Correa, Diaz-Canel...

Sorry for this, but your friends are clearly on the second group. They are looking who to blame, don't understand what for, perhaps to kill or imprison them. Decolonialism has failed. Deglobalization has and will always fail (maturity is not about isolation; it's not about dependence, it's not about independence: it's about interdependence). The best examples are North Korea, Cuba, Venezuela and Argentina. They reject modernity (we are not anymore there, anyway, your friends can just create their own social experiments, living like in 1700), capitalism (ask them to give the example, stop accumulating capital and share all their goods, right now!). When they pay taxes, they are supporting colonialism. Ask them to stop buying foreign products, stop paying taxes, stop using the internet, stop learning foreign languages, etc. Otherwise (if your friends don't act, dont donate their goods, don't crush their mobile phones, don't go living in communist kibbutz), those are just empt y words, which just expose their frustrations and anguish of blaming other for their own fails. Not trying to be mean here, but this is a common and predictable social pattern based on dogmas, which provides good amounts of votes to the left.