I want to opt philosophy having no prior knowledge of the subject. Please guide me whether it's combination with Indo-Pak history, I.Law and Pashto will be a good option. Please, also recommend me some books on the this subject.

If you have no prior knowledge of it then I will advise you to go through some online books and notes of philosophy e.g. Copi's or Hurley's books on Logic and philosophies of Muslims and Western philosophers, then you will be in a better position to take decision but be careful! Never Never Never decide in hurry after reading just one page of first chapter. Better to do thorough analysis of each and every chapter to find whether you can digest it or not because you can't get good marks in CSS Exams without deep understanding of contents of subjects.

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"And whoever puts all his trust in ALLAH, He will be enough for him" (Al-Quran 65:1)

thank you so much Daisy. Are these books only to grok the initial concepts of philosophy, or are these advanced books?

Although i have studied Positivism, Dialectical Materialism etc but still i want to get hold of a simple, easy to understand book, in order to understand how technical the theories are to grasp.

Yes! That's good combination....which is greatly helpful in relation to compulsory subjects...Indo-Pak history in Pakistan & Current Affairs etc while Philosophy in Essay paper...!
Secondly, Philosophy is high-scoring subject which will also increase your critical, analytical and argumentative skills....In CSS Essay paper 2014, there were three completely philosophical essays such as "Language is a Fit Data for Research in Humanities & Social Sciences" & "Can Meaning Be Fixed?" (These topics are totally related with Philosophical theories i.e. Pragmatism, Logical Positivism, Analytic Philosophy, Structuralism, Hermeneutics etc.).

After all, You need:
For Paper I:
A Concise Introduction to Logic by Patrick J. Hurley
For Paper II:
History of Philosophy Eastern & Western by Radhakrishnan
Studies in Muslim Philosophy by M. Saeed Sheikh

thank you sir for your encouraging reply. Yes, indeed CSS 2014 exam also tested the philosophical side of the candidates.. In fact i want to replace my old optional's (Journalism and Sociology) with Philosophy

In Css 2003, there was a complete essay on "existentialism".. So philosophy is getting increased importance in CSS

another question is..

that is Philosophy a subject to be crammed??

Yes! For some students, it may be a subject to be crammed because of their furious cramming skills......but keep in mind.....philosophy being crammed may not make you improve your cognitive and argumentative skills...you can consult a competent teacher....because, in this way, you'll not only be able to cover both papers thoroughly in less than 20 days (rather than 1.5-2 months) but also be able to learn strategies to get numbers in 90 plus range (especially in Logic).

"Phir Uss Ke Baaad Tera Faisla...Jo Tu Chaaahey...!"

do you know any teacher of philosophy in Islamabad?

I'm afraid that you may not get there any competent teacher....coz there is no noticeable institution/university to teach philosophy in Islamabad.....So you've to move towards Lahore for some days...!

These books cover complete syllabus of paper 1 and are easy to understand as well for initial concepts. However some efforts are needed to collect material for paper 2. But for that too "History of Muslim Philosophy" covers most of the topics as it contains chapters on almost all the muslim Philosophers and other topics.

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"And whoever puts all his trust in ALLAH, He will be enough for him" (Al-Quran 65:1)