OK, I've avoided commenting on this thread for a few days...
Can "Knife Fighting" be learned alone?
No, it cannot. Fighting takes two people (at least).
Can "Knife Fighting" be learned at home?
I'm assuming here that you mean, "without an instructor." You
can learn how to fight, with
anything, without the aid of an instructor. I say this with 100% authority because, frankly, it's been done before. Fighting started somewhere and with someone who had no actual instruction. So, yes, it can be done. The problem is, it is the
least efficient way of learning out of thousands of different ways. It involves a lot of trial and a lot of error. When your fighting unarmed, error can, and has, lead to serious, sometimes fatal, injury. Adding weapons in only increases the odds of injury. Often, starting from scratch can take (literally) generations of practitioners to refine and fully realize "fighting" with any given medium. Modern MMA, for instance, is the product of at least 15 "generations" of refinement. If you restrict it to only those generations since UFC1, then it is the product of no less than 3 "generation" of refinement (based on instructor-student-instructor cycling). The first generation of "Knife Fighters" survived by accident, learned by experience of actually killing other people, and learned by watching their friends and students get killed. You don't wanna start there.
I suppose part of the question is also, "can I learn, without live instruction, by book and video?" The answer is still a qualified "yes." You can learn but it'll be a boatload slower. You
WILL make mistakes. Without a live instructor to see and correct those mistakes, they will creep into your personal repertoire, each mistake and error dominoing off of the previous, expanding in a Butterfly Effect to where your skills are naught but a house of cards ready to collapse when the first skilled opponent exploits one of your foundational errors (stance, distance, footwork, timing, grip, whatever). Again, these errors can be mitigated by "going and doing" but who wants to kill people and risk getting killed just to make sure you don't have any foundational errors screwing your technique up?
Dead Weapons
In a way, this is pretty academic. "Knife Fighting" is a "DEAD WEAPON" area of study in the modern industrialized world. No one in industrialized western civ. fights knife-vs-knife any more. Yes there are exceptions to the rule. The exceptions prove the rule. So, unless you're planning on spending a lot of time in 3rd World areas that are so poor that even the local "rich" don't have guns for criminals to steal and misuse, the whole idea of knive-vs-knife is restricted to academics, hobbyists, and wannabes.
That is not to say that the knife has no value as a Self Defense tool. But, in those cases, a knife as a SD tool is almost always going to be asymmetrically paired. A knife-using SD person will most likely be deploying his (her?) knife against someone who doesn't have a knife. They might have a gun, a stick, or superior numbers. Knife-vs-knife is
rare! So, unless you're an academic or hobbyist interested in seeing how it was historically done in a given culture or in preserving a skill which may not be too useful in modern society (Flint Knapping anyone?), then "Knife Fighting" is probably not what you're really interested in (I'm assuming you're not a wannabe).
In that case, you need to learn how to carry, deploy, and use a knife in non-knife fighting roles and the legal restrictions, responsibilities, and repercussions of doing so. Videos and books can still help (arguably are even more valuable in this role) but you still need a partner to train with and live instruction still keeps errors from slipping in.
As for FMA and WMA (Western Martial Arts)/Medieval Dagger...
They, and most any other martial art that teaches knife-vs-knife is "Dead Weapon." Some are more "dead" than others. Every "knife style" is developed within its own context and optimized for that context. There are hundreds of variables which affect how a blade and the fighting style for using that blade are developed. The short list includes:
- What materials are available to make the blades from (stone, copper, bronze, iron, steel???)
- What is the likelihood of the opponent wearing armor, either deliberate or improvised, and what form will that armor take (heavy cloth, reinforced cloth, leather, bronze/iron/steel???)
- Are there any legal restrictions the what size and configuration of the blade?
- Are there any social restrictions on the size and configuration of the blade?
- Are there any legal (or social) restrictions on who may use a knife or who you may use a knife against
- Are there any legal (or social) restrictions on what techniques may be used (are certain killing or maiming blows disallowed? is there greater social status gained from scarring instead of killing?)
I'm sure you can think of a dozen more, but you get the idea.
When you compare Medieval Dagger to most FMA, they look almost nothing alike. Is this because one is "cooler" or "more effective" than the other? Obviously not. Both are extremely effective and highly optimized for the context in which they evolved. There are a lot of advocates for FMA who look at Medieval Dagger and (at the most charitable) think, "I'd kill him in a heartbeat." Well, sure, if you're all setting around in the Philippines and dressed for the climate. Take a native Philippine and drop him into the middle of "The Little Ice Age" and see how well he does (if he doesn't freeze to death first).
The simple fact is that both FMA and Deggen are optimized for a physical and social climate which is
different from that of most of the Industrialized West and modifications have to be made to each in order to adapt it to Western social/physical climate. Now, to be perfectly honest with you, I think that most FMA's require far less adaptation than Deggen and many FMA's taught here in the West have already been adapted so, just speaking personally, a FMA school near you would probably be a better bet than a WMA school if you're looking for Self Defense with a knife.
I think this reply is turning into a Thesis so that'll be enough for now.
Peace favor your sword,
Kirk